diff --git a/content/commands.js b/content/commands.js
index f3f0fdd7..25df755d 100644
--- a/content/commands.js
+++ b/content/commands.js
@@ -483,18 +483,62 @@ function Commands() //{{{
                   "Here, downloads can be paused, canceled and resumed."
         }
     ));
-    addDefaultCommand(new Command(["ec[ho]"],
-        function(args) { vimperator.echo(args); } ,
+
+    function argToString(arg, color)
+    {
+        if (!arg)
+            return "";
+
+        try
         {
+            // TODO: move to vimperator.eval()?
+            arg = eval(arg);
+        }
+        catch (e)
+        {
+            vimperator.echoerr(e.toString());
+            return null;
+        }
+
+        if (typeof arg === "object")
+            arg = vimperator.objectToString(arg, color);
+        else if (typeof arg === "function")
+            arg = arg.toString().replace(/</g, "&lt;").replace(/>/, "&gt;");
+        else if (typeof arg === "number" || typeof arg === "boolean")
+            arg = "" + arg;
+        else if (typeof arg === "undefined")
+            arg = "undefined";
+
+        return arg;
+    }
+    addDefaultCommand(new Command(["ec[ho]"],
+        function(args)
+        {
+            var res = argToString(args, true);
+            if (res != null)
+                vimperator.echo(res);
+        },
+        {
+            usage: ["ec[ho] {expr}"],
             short_help: "Display a string at the bottom of the window",
-            help: "Echo all arguments of this command. Useful for showing informational messages.<br/>Multiple lines can be separated by \\n."
+            help: "Useful for showing informational messages. Multiple lines can be separated by \\n.<br/>" +
+                  "<code class=\"argument\">{expr}</code> can either be a quoted string, or any expression which can be fed to eval() like 4+5. " +
+                  "You can also view the source code of objects and functions if the return value of <code class=\"argument\">{expr}</code> is an object or function.",
+            completer: function(filter) { return vimperator.completion.javascript(filter); }
         }
     ));
     addDefaultCommand(new Command(["echoe[rr]"],
-        function(args) { vimperator.echoerr(args); } ,
+        function(args)
         {
+            var res = argToString(args, false);
+            if (res != null)
+                vimperator.echoerr(res);
+        },
+        {
+            usage: ["echoe[rr] {expr}"],
             short_help: "Display an error string at the bottom of the window",
-            help: "Echo all arguments of this command highlighted in red. Useful for showing important messages."
+            help: "Just like <code class=\"command\">:ec[ho]</code>, but echoes the result highlighted in red. Useful for showing important messages.",
+            completer: function(filter) { return vimperator.completion.javascript(filter); }
         }
     ));
     addDefaultCommand(new Command(["exe[cute]"],
@@ -601,7 +645,11 @@ function Commands() //{{{
             help: "Acts as a JavaScript interpreter by passing the argument to <code>eval()</code>.<br/>" +
                   "<code class=\"command\">:javascript alert('Hello world')</code> would show a dialog box with the text \"Hello world\".<br/>" +
                   "<code class=\"command\">:javascript &lt;&lt;EOF</code> would read all the lines until a line starting with 'EOF' is found, and will <code>eval()</code> them.<br/>" +
-                  "The special version <code class=\"command\">:javascript!</code> will open the JavaScript console of Firefox."
+                  "The special version <code class=\"command\">:javascript!</code> will open the JavaScript console of Firefox.<br/>" +
+                  "Rudimentary <code class=\"mapping\">&lt;Tab&gt;</code> completion is available for <code class=\"command\">:javascript {cmd}&lt;Tab&gt;</code> (but not yet for the " +
+                  "<code class=\"command\">:js &lt;&lt;EOF</code> multiline widget). Be aware that Vimperator needs to run {cmd} through eval() " +
+                  "to get the completions, which could have unwanted side effects.",
+            completer: function(filter) { return vimperator.completion.javascript(filter); }
         }
     ));
     addDefaultCommand(new Command(["let"],
@@ -915,7 +963,7 @@ function Commands() //{{{
                   "</ol>" +
                   "You WILL be able to use <code class=\"command\">:open [-T \"linux\"] torvalds&lt;Tab&gt;</code> to complete bookmarks " +
                   "with tag \"linux\" and which contain \"torvalds\". Note that -T support is only available for tab completion, not for the actual command.<br/>" +
-                  "The items which are completed on <code>&lt;Tab&gt;</code> are specified in the <code class=\"option\">'complete'</code> option.<br/>" +
+                  "The items which are completed on <code class=\"mapping\">&lt;Tab&gt;</code> are specified in the <code class=\"option\">'complete'</code> option.<br/>" +
                   "Without argument, reloads the current page.<br/>" +
                   "Without argument but with <code class=\"command\">!</code>, reloads the current page skipping the cache.",
             completer: function(filter) { return vimperator.completion.get_url_completions(filter); }
diff --git a/content/completion.js b/content/completion.js
index a827ac57..0e0f9972 100644
--- a/content/completion.js
+++ b/content/completion.js
@@ -473,6 +473,73 @@ vimperator.completion = (function() // {{{
             return build_longest_common_substring(mapped, filter);
         }, //}}}
 
+        javascript: function(str)
+        {
+            g_substrings = [];
+            var matches = str.match(/^(.*?)(\s*\.\s*)?(\w*)$/);
+            var object = "window";
+            var filter = matches[3] || "";
+            var start = matches[1].length-1;
+            if (matches[2])
+            {
+                var brackets = 0, parentheses = 0;
+                outer:
+                for (; start >= 0; start--)
+                {
+                    switch (matches[1][start])
+                    {
+                        case ";":
+                        case "{":
+                            break outer;
+
+                        case "]":
+                            brackets--;
+                            break;
+                        case "[":
+                            brackets++;
+                            break;
+                        case ")":
+                            parentheses--;
+                            break;
+                        case "(":
+                            parentheses++;
+                            break;
+                    }
+                    if (brackets > 0 || parentheses > 0)
+                        break outer;
+                }
+            }
+            object = matches[1].substr(start+1) || "window";
+
+            var completions = []; 
+            try
+            {
+                completions = eval(
+                    "var comp = [];" +
+                    "var type = '';" +
+                    "var value = '';" +
+                    "var obj = eval(" + object + ");" +
+                    "for (var i in obj) {" +
+                    "     try { type = typeof(obj[i]); } catch (e) { type = 'unknown type'; };" +
+                    "     if (type == 'number' || type == 'string' || type == 'boolean') {" +
+                    "          value = obj[i];" +
+                    "          comp.push([[i], type + ': ' + value]); }" +
+                    // The problem with that is that you complete vimperator.
+                    // but can't press <Tab> to complete sub items
+                    // so it's better to complete vimperator and the user can do
+                    // .<tab> to get the sub items
+                    //"     else if (type == 'function') {" +
+                    //"          comp.push([[i+'('], type]); }" +
+                    //"     else if (type == 'object') {" +
+                    //"          comp.push([[i+'.'], type]); }" +
+                    "     else {" +
+                    "          comp.push([[i], type]); }" +
+                    "} comp;");
+            } catch (e) { completions = []; };
+
+            return build_longest_starting_substring(completions, filter);
+        },
+
         exTabCompletion: function(str) //{{{
         {
             var [count, cmd, special, args] = vimperator.commands.parseCommand(str);
diff --git a/content/vimperator.js b/content/vimperator.js
index 6d192f4d..c2ca5035 100644
--- a/content/vimperator.js
+++ b/content/vimperator.js
@@ -434,36 +434,87 @@ const vimperator = (function() //{{{
             }
         },
 
-        // logs a message to the javascript error console
-        log: function(msg, level)
+        // if color = true it uses HTML markup to color certain items
+        objectToString: function(object, color)
         {
-            // if (Options.getPref("verbose") >= level) // FIXME: hangs vimperator, probably timing issue --mst
-                console_service.logStringMessage('vimperator: ' + msg);
-        },
-
-        // logs an object to the javascript error console also prints all
-        // properties of the object
-        logObject: function(object, level)
-        {
-            if (typeof object != 'object')
+            if (object === null)
+                return "null";
+            if (typeof object != "object")
                 return false;
 
-            var string = object + '::\n';
+            var string = "";
+            var obj = "";
+            try { // for window.JSON
+                obj = object.toString();
+            } catch (e) {
+                obj = "&lt;Object&gt;";
+            }
+
+            if (color)
+                string += "<span style=\"color: magenta; font-weight: bold;\">" + obj + "</span>::\n";
+            else
+                string += obj + "::\n";
+
             for (var i in object)
             {
                 var value;
                 try
                 {
-                    var value = object[i];
+                    if (i == "JSON") // without this ugly hack, ":echo window" does not work
+                        value = "[object JSON]";
+                    else
+                        value = object[i];
                 }
                 catch (e)
                 {
                     value = "";
                 }
 
-                string += i + ": " + value + "\n";
+                if (color)
+                {
+                    // syntax highlighting for special items
+                    if (typeof value === "number")
+                        value = "<span style=\"color: red;\">" + value + "</span>";
+                    else if (typeof value === "string")
+                    {
+                        value = value.replace(/\n/, "\\n").replace(/</, "&lt;");
+                        value = "<span style=\"color: green;\">\"" + value + "\"</span>";
+                    }
+                    else if (typeof value === "boolean")
+                        value = "<span style=\"color: blue;\">" + value + "</span>";
+                    else if (value == null || value == "undefined")
+                        value = "<span style=\"color: blue;\">" + value + "</span>";
+                    else if (typeof value === "object" || typeof value === "function")
+                    {
+                        // for java packages value.toString() would crash so badly 
+                        // that we cannot even try/catch it
+                        if (/^\[JavaPackage.*\]$/.test(value)) 
+                            value = "[JavaPackage]";
+                        else
+                        {
+                            var str = value.toString();
+                            if (typeof str == "string")  // can be "undefined"
+                                value = str.replace(/</g, "&lt;").replace(/>/g, "&gt;");
+                        }
+                    }
+                    
+                    string += "<span style=\"font-weight: bold;\">" + i + "</span>: " + value + "\n";
+                }
+                else
+                    string += i + ": " + value + "\n";
             }
-            vimperator.log(string, level);
+            return string;
+        },
+
+        // logs a message to the javascript error console
+        // if msg is an object, it is beautified
+        log: function(msg, level)
+        {
+            //if (Options.getPref("verbose") >= level) // FIXME: hangs vimperator, probably timing issue --mst
+            if (typeof msg == "object")
+                msg = this.objectToString(msg, false);
+
+            console_service.logStringMessage('vimperator: ' + msg);
         },
 
         // open one or more URLs