When I upgraded to Firefox 2.0, I ran through my extensions to see what was new, and I noticed the Stylish extension had a link to a site to “get more styles”. I was blown away by the number of styles you can get for not only web sites, but also to change the look and feel of Firefox itself. Not many people realize that the look and feel of Firefox itself is controlled by CSS.
One of the great things about it is the ease with which you can “install” these styles. If you have Stylish already installed, you simple click “save” on the Userstyles.org page and it drops it in there for you. If you know what you’re doing, you can edit them some (which I have already on several).
So what did I get? I got one to turn the active tab blue in firefox, so it stands out more. I also got one that rounds the corners of text input boxes in Firefox (NOT in web pages). I also updated a few that change how some sites look. There are a couple (that I didn’t get) which do things like totally re-skin gmail and hotmail etc.