I'd learn shit. Seriously, there's a lot of learning I want to do. Personally, I have things like programming, web design, linux, and other languages on my list. One of those may apply to you, but I'm sure there are other things you've wanted to figure out how to do which don't involve walking.
There's actually a part of me that is jealous because it would be nice to have some time in which I couldn't do other things so I would be forced to take the time to learn the things I've been planning.