I used to bite my fingernails, but I gave it up "Cold turkey" and haven't done it since. Been about 2 years now heh.

I was wondering what habits anyone else might have.

Funny you say that, i stopped biting mine all of a sudden and its been about 2 months now. On occasional nervous trips, i find my fingers back in my mouth :[

I quite smoking december 18th 2004 and I quite caffiene two months ago
I was drinking was too much coffee and energy drinks all day

Up to about two years ago I used to drink a Big Gulp of coke every morning....no wonder I was so wired.