While I personally prefer Safari or Camino to it, Firefox is the dominant force in the browser market. Version 3 went a long way to making itself fit in on Macs, but it’s not as close as I’d personally like (and it may never get there). They’re now asking for your help to shape future versions of the browser.
You don’t need to have a degree in computer science or even supreme hacking skills. You just need an imagination and a will to make your idea available under one of a couple licenses. There’s a couple videos to get your imagination started and show you how you can contribute.
If I were to participate, I’d be fairly glib and simply send them a video of Camino and someone using all Cocoa supplied features. I understand that Firefox needs to use XUL. It doesn’t make me happy though.
A checkbox to turn off that stupid Awesome Bar is all I'd need.