Computers. I've been working (and playing) at programming them since 1978 and haven't got bored yet. I listen to music -- even when nobody else can hear it -- and read, often with a cat as a helper. I enjoy photography and playing about with images digitally. I've had a long-time interest in sports simulation games, both as board games and on a computer.
In the summer of 2004, I (kind of) sang and (theoretically) played a couple of songs at a house filk as the first musical performance of my adult life. Filk has now taken over a great amount of my spare time, especially since FKO 15, inspiring me to pick up a guitar, write songs, and generally reach a new level of obsession about musical things.
(In March 2008, I started speculating on whether it would be a good idea to record a CD of original filk material. For anyone who is interested in taking part in that discussion, I'm posting plans and progress...and a lot of questions, using the LJ account butifidid.) With the release of Rain on the Sand in early 2009 (see Website link), the account mentioned above became mostly of historical interest. Things change, though, and butifidid found a new life as I work toward a second, mostly digital release.