firefox extension

This looks potentially very useful for automated testing.

AllPeers.com/ combines BitTorrent and Firefox to allow you to easily share webpages, photos, videos, movies or any file of any size directly inside the Firefox browser with your friends and family.
https://addons.mozilla.org/de/firefox/addon/3234

IE Tab - an extension from Taiwan, features: Embedding Internet Explorer in tabs of Mozilla/Firefox.
For the Younglifers who can't view Young Life pages in Firefox.
This converts a firefox tab into Internet Explorer

Everybody’s favorite open-source browser, Firefox, is great right out of the box. And by adding some of the awesome extensions available out there, the browser just gets better and better.

But look under the hood, and there are a bunch of hidden (and some not-so-secret) tips and tricks available that will crank Firefox up and pimp your browser. Make it faster, cooler, more efficient. Get to be a Jedi master with the following cool Firefox tricks.

Video Downloader 2.0 and VideoDownloader 1.O Firefox Extension allows you to download videos (to your computer)

ステータスバーにローマの気温を表示するサンプル。なんだそりゃ.... ブックマークのRSS拡張でflockみたいにバックエンドがdel.icio.usとかふつうにできそうなきがしてきた。

This is a really good idea

Definite must-have extension -- basically gives you a "run" option for executable files (e.g. installers) in Firefox (ala IE).

Quoted: This is a mozilla extension that allows you to open ANY file (executables, etc.) from the internet into the default program assigned by your operating system, without needing to save it first.