Forgive me if there's a section for such suggestions.
There are a few projects close to my heart that I use daily and felt the need to share.
First: Conkeror.
www.conkeror.org
Conkeror was originally a Firefox plugin, but now is a (phonetically confusable with Konqueror) standalone browser based on XUL 1.9. It's main author is Shawn Betts of Ratpoison and StumpWM(my current WM) fame.
It acts as much like Emacs as possible, with extensions/customisations written in JavaScript, as opposed to ELisp.
Conkeror is in very active development, and the barrier for entry is low. Basically make your code modular, compact and readable. I've written none of it for those reasons. (haha)
It, like GTK Emacs, allows you to use the mouse, but virtually everything can be done with the keyboard. Actually, it lacks any toolbars, but as I recall you can turn on tabs. Flash and some Java can be problematic there, but there's work being done on scripts to deal with such corner cases.
Nearly all Firefox 2 plugins work. Flash and Adblock Plus are all I use personally.
I have been using it for months now, with a total of 4 crashes, and a few restarts, all can be traced back to the proprietary flash plugin.
Anyone who has experience with an Emacs should feel right at home. Even a stranger to Emacs will be able to get basic browsing done within minutes due to the help screen being the first thing to display, and the Emacs-like built-in Help system. As a matter of fact, I was largely a vi user and had Emacs around for working with Common Lisp. Originally, I started using Conkeror to get more of my screen real estate back, since I couldn't turn off enough of Firefox's toolbars (IE all of them). I am now completely addicted to Emacs(en). It's one hell of a gateway drug!
There are .debs available here:
http://noone.org/debian/
but dealing with the git version is fairly easy.
Unfortunately, I spent about an hour reading the build/install scripts the first time I installed it. Anyone who has more experience with scripting should be able to do it in 10 minutes.

Meld
Meld is a cool program for visually, gui that is, "diff" out files. It's nice and worth a look. I use it to see what changes happened to a file, and it gives you another view into a file beyond your only current tool, diff.