Emacs user for more than 4 years, since I started my PhD thesis (in Mathematics), when I needed a good cross-platform editor. I already knew a little emacs from my Lisp-love, and vi from being the editor of choice in the first courses… It is still the editor of choice among the department staff. I pity them, poor Satan lovers.
I have small experience in editing emacs lisp (mostly to repair some minor errors I have encountered sometimes, or adding a small funcionality I like), now I am writing a major mode to interact with my fractal drawing console programs, via command line arguments. For now, it can load the image and zoom in from a “drag and drop” over that image, reload and repeat (over the same buffer, still buggy thus). But it is getting better 
If you want to know something else,
Only emacs related posts at my blog
My personal page at the department
I started a 30 day challenge on 1st December 2010 in which I would use only emacs (as far as possible) to do all my standard work stuff. You can read more about this in the following posts:
Emacs 30 Day Challenge Update 1: Writing this in conkeror
Emacs 30 Day Challenge: Using gnus to read mail (as a newbie!)
Emacs 30 Day Challenge: A glimpse of bbdb, The Insidious Big Brother Database and gnus
Some interesting posts in my blog:
Using valgrind inside emacs with click+go capabilities
Syncing iPod's vMac and Linux: emacs on iPod Touch (somehow, not native, not much useful, be warned)
Welcome to the wiki. – DrewAdams