Had a friend who tried it as well for a while.
Did not last, in the end you build up such a sleep-shortage, that your body simply forces you to sleep through any and all kind of alarms you set, in order to set your counter at 0 again.
It's not healthy, but mostly, it's pointless... The rest of the world around you doesn't follow this practice, and in the end, you have some more time during the night, but you lose time during the day, when you could be interacting with people.
In case you're curious:
http://blog.rykus.com/2009/04/05/sle...ent-conclusion