While creating/editing CSS files, viewing the output instantly saves much time.

CSSrefresh, a JavaScript file that auto-refreshes the web-page, was featured before at WRD.

SoFresh!

SoFresh!, a bookmarklet, extends it a little further, works without inserting a JS file to our web pages and allows us to choose which CSS file to refresh.

In case you don't have such a live-updating development environment, you should definitely give this tool a try.

WebResourcesDepot Feed