[`p r o x y]

окей, а как вот такой вариант:

// When a generated page (in PHP, Perl or something else)
// need add to each post (DIV, TABLE, TR, TD): onmouseover="qq.Nick='user nick'"
// Exsample for PHP: echo '<tr class="bugnote" id="'.$postId.'" onmouseover="qq.Nick=\''.$userNick.'\'">';

var qq = {

	// QuickQuote Settings
	LinkShowTime	: 3000,
	LinkId  		: 'quickQuote',
	LinkStyle		: 'z-index:1000; cursor:pointer; position:absolute; visibility:hidden',
	LinkText		: '<b>Цитировать</b>',
	TextAreaId   	: 'bugnote_text', // id or name
	// <--------------------
	
	Link : '', TextArea : '', Text : '', Nick : '', TimerId : '',
	
	Install		: function(){
		document.write(	'<div onmousedown="qq.InsertText()" onmouseout="qq.TimerStart()" onmouseover="qq.TimerStop()" \
						class="button" id="'+qq.LinkId+'" style="'+qq.LinkStyle+'">'+qq.LinkText+'</div>');
		
		qq.Link = document.getElementById(qq.LinkId);
		
		document.onclick   = qq.GetSelText;
		document.onmouseup = qq.LinkShow;
	},
	
	TimerStart	: function(){ qq.TimerStop(); qq.TimerId = setTimeout(qq.LinkHide, qq.LinkShowTime); },
	TimerStop	: function(){ clearTimeout(qq.TimerId); },
	LinkHide	: function(){ qq.Link.style.visibility = 'hidden'; },

	LinkShow 	: function(event){
		qq.GetSelText();
		if (qq.Text == '') return;
		
		var mc = event || window.event;
		if (mc.pageX || mc.pageY){
			mc.X = mc.pageX;
			mc.Y = mc.pageY;
		}else if (mc.clientX || mc.clientY){
			mc.X = mc.clientX + document.body.scrollLeft + document.documentElement.scrollLeft;
			mc.Y = mc.clientY + document.body.scrollTop  + document.documentElement.scrollTop;
		}
		qq.Link.style.left = (mc.X-35)+'px';
		qq.Link.style.top  = (mc.Y+11)+'px';
		qq.Link.style.visibility = 'visible';
		
		qq.TimerStart();
	},
	
	GetSelText	: function(){
		qq.Text = getSelText();
		qq.Text.replace(/(\r?\n\s*){2,}/gi,'\r\n').replace(/^\s+|\s+$/gi,'').replace(/(\ |\t)+/gi,' ');
		if (qq.Text == '') qq.LinkHide();
	},
	
	InsertText	: function(){
		qq.LinkHide();
		if (qq.TextArea == '' || qq.TextArea == null){
			qq.TextArea = document.getElementById(qq.TextAreaId);
			if (qq.TextArea == null) qq.TextArea = document.getElementsByName(qq.TextAreaId)[0];
		}
		if (qq.TextArea == null) return;
		
		if (navigator.appName == 'Opera') qq.Text = '[q]'+qq.Nick+': ' + qq.Text + '[/q]\r\n';
		else qq.Text = '[q]'+qq.Nick+': ' + qq.Text + '[/q]\n';
		
		insertText(qq.TextArea, qq.Text);
	}
};

// Common functions
function saveCaretPos(event){
    event = event || window.event;
    var obj = event.target || event.srcElement;
    if (typeof(document.selection) != 'undefined' && typeof(document.selection.createRange) != 'undefined')
    obj.caretPos = document.selection.createRange().duplicate();
}
function getSelText(){
	if (window.getSelection && !window.opera) 	var selText = window.getSelection(); // ff
	else if (document.getSelection) 			var selText = document.getSelection(); // opera
	else if (document.selection) 				var selText = document.selection.createRange().text; // ie
	if (!selText) selText = '';
	return selText.toString();
}
function insertText(obj, text){

	var scrollTop, scrollLeft;
	if (obj.type == 'TEXTAREA' && obj.scrollTop){
		scrollTop = obj.scrollTop;
		scrollLeft = obj.scrollLeft;
	}

	if (window.getSelection || document.getSelection) var caretPos = obj.selectionStart + text.length;
	
	if (obj && obj.caretPos) 
		obj.caretPos.text = text;
	else if (obj && obj.selectionStart+1 && obj.selectionEnd+1)
		obj.value = obj.value.substring(0, obj.selectionStart) + text + obj.value.substring(obj.selectionEnd, obj.value.length);
	else if (obj)
		obj.value += text;
	
	if (window.getSelection || document.getSelection) obj.setSelectionRange(caretPos, caretPos);
	
	if (typeof scrollTop != 'undefined'){
		textObj.scrollTop = scrollTop;
		textObj.scrollLeft = scrollLeft;
	}
}
// <--------------------

// Install QuickQuote
qq.Install();

document.body.onload = function(){
	qq.TextArea = document.getElementById(qq.TextAreaId);
	if (qq.TextArea == null) qq.TextArea = document.getElementsByName(qq.TextAreaId)[0];
	if (qq.TextArea == null) return;
	
	qq.TextArea.onselect = saveCaretPos;
	qq.TextArea.onclick  = saveCaretPos;
	qq.TextArea.onkeyup  = saveCaretPos;
}
// <--------------------

Осталось только разобраться с прокруткой в textarea.
Demo страница