I was going to post this in the thread in health as well, but I wanted to add it here too. I'm also one of those people that can't wake up even though I did have to wake myself up in the morning. I still have to wake up at 7 most mornings, but it was so hard that I would have to set the alarm for 6 and hit snooze every 10 minutes for an hour until I could gradually wake up. I'm sure it has something to do with my body, but I've never bothered to look into it. Instead, and I'm begging everyone to at least try not to laugh, but I had to resort to getting this thing, and it has actually saved me:
The way it works is that the alarm goes off and the top explodes, sending 4 puzzle pieces flying. You can't turn off the alarm any way you try. You can't even take out the batteries because you need a screwdriver to do it. Your only choice for shutting that thing up is to physically get up, look for the puzzle pieces, put the puzzle together, press it down and while you're pressing it down press the off button. The idea is that by the time you get together the motor skills and concentration to do this, you will be awake enough to not go back to sleep.
It's almost embarassing how much I know about *ahem* "alternative" alarm clocks, but Clocky (the run away one that someone posted up there) doesn't actually run far enough, so I don't think it's worth it. There is also another alternative that gradually lights up the room so that you are naturally awake by the time the alarm goes off, but it's over $100 and I don't think it would work. If you're a heavy sleeper like I am, someone could turn a spotlight on over you and you wouldn't even flinch.