Speaking of stairs, designing an FRC sized legged robot would be a great exercise, and if you can figure it out, might even work in a real game.
My son's friend Matt made a smaller one, and although the mechanics would probably have to be quite different (crankshafts/connecting rods for legs?) the programming could be similar. You never know where this kind of thing will lead.
http://www.technewsarizona.com/Artic...0091220&t=0600