I encountered a post about this odd little game on CrunchNotes last night. It's called Line Rider, and it's a Deviant Art project created by a user named ~fsk. There isn't really a point beyond art for art's sake, but it's totally fun and addictive. You draw a line to create a two dimensional rolling hillscape, then you click play and watch your little sled buddy slide down the thing. Faceplant, repeat.
It seems that this game has gathered a huge cult following. Running a search for Line Rider on YouTube yields hundreds of videos of tracks, jumps, halfpipes and other courses people have designed within the last two weeks. Some folks have way too much time on their hands.
Now if you'll excuse me...