A CSS Wish
Here's something I'm looking for. I want the ability to style sites the way I want. For example, the new Wired site is designed so that it's entire presentation is controlled by CSS stylesheet rules. Well, I happen to like the way it looks, but maybe I want it to use a slightly different color scheme. Or perhaps a different font for the sidebar. Or maybe I want to adjust the line spacing for the articles? Well, I realize that both the Internet Explorer and Mozilla browsers allow a user-defined stylesheet. But here's the problem: I don't want these custom CSS rules to be applied to ALL sites, just to wired.com.
This may never happen for Internet Explorer, but considering that Mozilla is open source and all, I could see a new mozdev.org project for this feature. I'd write it myself, but I have absolutely no experience developing with Mozilla. It's something I really want though, so I may have to take that plunge if someone doesn't beat me to it.
Another approach to this feature would be to use a proxy engine. The Proxomitron would work-- it's customizable enough that it could do this, and it will work with Internet Explorer. But I'd still prefer a native Mozilla extension.
Update: Yes, the Proxomitron can do this trick. Creating a custom web page filter for Wired.com:
URL Match: *.wired.com
Matching Expression: http://*.akamai.net/*/www.wired.com/*/wnScreen.css
Replacement Text: http://bradchoate.com/play/wired.css
My custom stylesheet just so happens to hide a few of the ads and sets the font for the articles to Times New Roman. It inherits the existing stylesheets, but adds new CSS rules with the "!important" marker so they get enforced over the existing rules.