Design Challenge: Produce a Lot Quickly

Thursday I gave myself a design challenge:  produce 5 pairs of earrings in under 2 hours.  I got this idea from back in the day when I visited a friend in art school; she was given the task of producing 100 drawings/paintings in a week.  Or maybe it was 75.  I don't quite remember.  I just remember the point was to make yourself CREATE, and having to do a lot in a short amount of time was supposed to help you get the juices flowing.

I ended up making 5 pairs of earrings and a necklace in about 3 hours.  Here's a sneak peek at what I made:

What kinds of challenges do you give yourself to get the creative juices flowing?