How about having simple way for running javascripts on any web-page?
I have solution. All you need is to drag link below on your links toolbar.
Or just add this link to your favorites.

JSconsole

Of couse, you can try it before :). Just click on the link.
Dislike it? Just press the link again and all will disappear.
As usual I provide source code:

[link]

javascript:var%20sc%20=%20document.createElement(%22SCRIPT%22);sc.src=%22http://blogs.sun.com/ahot/resource/bin/javascriptconsole.js%22;document.body.appendChild(sc);void(1);

[javascriptconsole.js]

//mouse down on dragged DIV element
function startdrag(t, e) {
	if (e.preventDefault) e.preventDefault(); //line for IE compatibility
	e.cancelBubble = true;
	window.document.onmousemoveOld = window.document.onmousemove;
	window.document.onmouseupOld = window.document.onmouseup;
	window.document.onmousemove=dodrag;
	window.document.onmouseup=stopdrag;
	window.document.draged = t;
	t.dragX = e.clientX;
	t.dragY = e.clientY;
	return false;
}
//move the DIV
function dodrag(e) {
	
	if (!e) e = event; //line for IE compatibility
	t = window.document.draged;
	t.style.left = (t.offsetLeft + e.clientX - t.dragX)+"px";
	t.style.top = (t.offsetTop + e.clientY - t.dragY)+"px";

	t.dragX = e.clientX;
	t.dragY = e.clientY;
	return false;
}
//restore event-handlers
function stopdrag() {
   window.document.onmousemove=window.document.onmousemoveOld;
   window.document.onmouseup=window.document.onmouseupOld;
}
function WRITE(s) {
	document.getElementById('ScriptOutArea').innerHTML+= s.toString().replace("\n", "<BR>");
}
function runScipt() {
	new Function("{\n"+document.getElementById('ScriptArea').value+"\n}")();
	document.getElementById('ScriptOutArea').scrollTop = document.getElementById('ScriptOutArea').scrollHeight;
}
function clearOut() {
	document.getElementById('ScriptOutArea').innerHTML = "";
}
function onerrorscript(err) {
	document.getElementById('ScriptOutArea').innerHTML += "<FONT color=red>"+err.replace("\n", "<BR>")+"</FONT><BR>";
	document.getElementById('ScriptOutArea').scrollTop = document.getElementById('ScriptOutArea').scrollHeight;
}

function initJavaScriptConsole() {
	if (document.getElementById('javascriptconsolediv') != null) {
		document.body.removeChild(document.getElementById('javascriptconsolediv'));
		return;
	}
	s = "";
	s+="<TABLE cellpadding=1 cellspacing=0 width=400>";
	s+="<TR><TD><DIV style='background:#bbccdd;color:black;border:1px solid black;font:11px courier new' onmousedown=startdrag(getElementById('javascriptconsolediv'),event)>javascript console, Anton Teryaev, 2008</DIV></TD></TR>";
	s+="<TR><TD><DIV style='border:1px solid black;padding:0px'><TEXTAREA style='padding:0px;width:100%;height:200px;border:0px solid black' id=ScriptArea>";
	s+="i = document.getElementsByTagName('BR');\n";
	s+="WRITE('There are '+i.length+' BR elements here\\n');";
	s+="</TEXTAREA></DIV></TD></TR>";
	s+="<TR><TD><INPUT TYPE=BUTTON VALUE='run script' onclick=runScipt() style='width:100px;background:#eeeeee;color:black;border:1px solid black;font:11px courier new'> <INPUT TYPE=BUTTON VALUE='clear output' onclick=clearOut() style='width:100px;background:#eeeeee;color:black;border:1px solid black;font:11px courier new'></TD></TR>";
	s+="<TR><TD><DIV style='background:#eeeeee;overflow:auto;height:100px;color:gray;border:1px solid black;font:11px courier new' id='ScriptOutArea'>";
	s+="<i>Output area, use WRITE(string) function.</i><BR>";
	s+="</DIV></TD></TR>";
	s+="</TABLE>";

	var sd = document.createElement("DIV");
	sd.style.position="absolute";
	sd.style.background="white";
	sd.style.border="1px solid black";
	sd.style.font="11px courier new";
	sd.style.top = (document.documentElement.scrollTop+document.documentElement.clientHeight/2-180)+"px";
	sd.style.left = (document.documentElement.scrollLeft+document.documentElement.clientWidth/2-200)+"px";
	sd.id = "javascriptconsolediv";
	sd.innerHTML=s;

	document.body.appendChild(sd);

	window.onerror = onerrorscript;
	window.onscroll = onwinscroll;
}
function onwinscroll() {
	md = document.getElementById('javascriptconsolediv');
	if (md.offsetTop > document.documentElement.scrollTop+document.documentElement.clientHeight-350) md.style.top = (document.documentElement.scrollTop+document.documentElement.clientHeight-350) + "px";
	if (md.offsetTop < document.documentElement.scrollTop) md.style.top = document.documentElement.scrollTop + "px";
	if (md.offsetLeft < document.documentElement.scrollLeft) md.style.left = document.documentElement.scrollLeft + "px";
}
initJavaScriptConsole();