Here's a nifty tool for your bag of tricks: JavaScript snippet that tags HTML elements with browser- and OS-specific attributes so you can target browser- and OS-specific 'peculiarities' without resorting to the usual bizarro selector tricks or Internet Explorer-specific conditional comments.
Using this script, you can target browser-specific elements via simple CSS selectors as follows:
.ie6 #targetElement { border: solid 1px #eee; }
OS Codes
win - Microsoft Windows