Sleeping sitting up?

I've read that some meditators and lucid dreamers actually sleep sitting up but never hear much more about it than that. Well I tried it today (didn't go that well, lol). Do any of you do this? What is the basic method? Can you get a good nights sleep doing this?

I had a friend way back in primary school who told me he slept sitting up. His parents went to see someone in hospital one time and he stayed in my house over night. I remember waking up in the morning and he was asleep in the bed (i was on the floor) sitting up. In his PJ's wearing his trainers. My mum told his parents because she thought he was going to run out or something during the night and they told her they'd find him like this. They didn't know how he'd slept like that or nothing. He was always telling us how his friend Uncle Pete used to help him sleep and he had no Uncle Pete. He was a weird kid.