University. In my opinion, college is the best thing to do when you don't have something better to do, if you'll pardon the tautology. Universities put you in contact with lots of other smart people, with the resources and freedom to devote your effort to whatever serves your interests.
College. I'm on the ltwt rowing team, so that can take up as many hours per day as I want.
I'm also working on a couple of books. I have a full mindmap for one, so it's just a matter of translating it into prose. I write slowly, but hopefully I'll have a first draft that will be somewhat readable by others by the end of summer.
Thankfully I don't make them. I'm involved in the RoboCup project: www.robocup.org. But I'm in a 'league' where software is king and hardware is standard: the 4 Legged League. Here's the link: http://www.tzi.de/4legged/
But if you're into making robots, pretty much every other league in RoboCup (save simulation) does hardware: humanoids, coffee-can robots, rescue robots, etc.
So yeah, I program robotic dogs to play soccer. Pretty ridiculous concept, but it's darn cute.