stylish for firefox

i was messing around and following some rather deep links on some blogs i was reading and came across john hicks' site where he has been creating new skins for some web applications.  how you say?  well, unknown to me (i use IE mostly) there is a really cool firefox add-on called stylish, that enables you to create/manage custom stylesheets for specific urls.  so basically when you visit a url, you can say 'whenever i visit this url, use this stylesheet instead' and it renders how you want.

you may wonder why you would want to do that, and in most instances you may not.  well, john came up with a really good use for it for me.  i use google reader to read my feeds online.  i like the interface and thought it would be hard to improve on.  as well, i do like some of the mac interfaces when i do certain things at home on my mac.  john blended the two...here's my new reader view:

so using a custom stylesheet and stylish, he's able to create a pretty cool interface for reader...man this is the type of stuff i wish the IE add-on ecosystem had -- i tried to search to see if this could be done in IE, but couldn't quickly find anything.  thanks john!