I may have done one accidental 2 years ago. I caught my edge on the lip and came around going to land on my side. Had to do a quarter of a lincoln to land it and came down basically on 1 foot. Don't really know though since I was alone and it wasn't on video. Probably just looked retarded as fuck.
Yea it's definitely possible. Casabon is doing them all the time these days. The first one I ever heard of was Colby West at the 2007 JOI. He won the 360 contest with a sw cork 3 as seen in the first shot of this video, couldn't find any other angles:
this question gets asked at least once a month. People have been doing them for years, as seen in all the video evidence.
Notables:Andy Mahre - IDEAHenrik - Education of StyleCasabon - most recent freestyle.ch (http://vimeo.com/50756976)