edit textbox teh 1337 way!!1! (aka vim and Firefox)
If you want to please your nerdcore needs you can install mozex.
Once you have done this, configure it to work with vim; the configuration is quite straightforward.
Now you can show your über-1337 editing skillz to your friendz.
P.S. it would be great if vim were exactly in the textbox but probably this is impossible, any idea about it?
P.P.S. if you are self-destructive enough you can try vimperator :)