In reply to Hardeep Asrani.

Which is not entirely true. There is one (or more) extensions around that gives you some kind of auto-save/auto-update mode.

Haven't used them for ages, though.
It's much easier for me to test stuff right in Firebug, then go on with copying it right out of the "styles" tab, and inserting it into my CSS. Much more control. Also much quicker results, as these auto-update features tend to make the browser work very sloppy.

cu, w0lf.