I haven't quit a job in over 13 years now, but when I did, I put in a two week notice and left on good terms, with open invites to come back. That being said, if I had an A-hole boss and knew I had 0 chance of getting a decent reference, I wouldn't hesitate to walk with no notice. I'd rather never burn my bridges like that though, so I just hope it never has to happen like that. I have heard of people being let go as soon as they turned in their notice. My wife's uncle worked in the computer programming industry and has seen many times where an exiting employee was immediate escorted to his desk to get his personal items and escorted off the premises.
