I spend a lot of time on music (guitar mostly nowadays) and photography/videography. Of course both of these things get sucked right back into computing in the end, but they are still very different experiences overall and I find that they're both valuable to me. The photo/video stuff feeds heavily into my game development work too.

Playing the piano is a nice way to clear the mind. Other than that, no, I don't do anything else, but I don't consider that to be a bad thing. After all, being extremely focused on one particular thing is the strength of a geek, and is what enables us to do what we do.

Not every hobby I have involves a computer, but a good chunk do!

Non-computer hobbies:

Playing Magic
Playing Guitar/Piano

Reading

Writing short stories (ok, arguably that's mostly done on a computer, but a lot of my writing I do inside of notebooks first, then transfer over)

Photography (again, editing/uploading is done in a computer, but the initial shooting is the most enjoyable part for me)
Videography (see above parenthesis ^^^)

Seems like music is a big one. I know a lot of programmers who are also good musicians. It must be the way our brains are wired.

I took up photography a few years ago. It has been very satisfying (and quite a money sink as well).

businesses.

What do you do with businesses for a hobby?