This is pretty ingenious, but seems impractical. (full article quoted below)

Can't get out of bed in the morning?

Scientists at MIT's Media Lab in the United States have invented an alarm clock called Clocky to make even the doziest sleepers, who repeatedly hit the snooze button, leap out of bed.

After the snooze button is pressed, the clock, which is equipped with a set of wheels, rolls off the table to another part of the room.

"When the alarm sounds again, simply finding Clocky ought to be strenuous enough to prevent even the doziest owner from going back to sleep," New Scientist magazine said on Tuesday.