generally i prop the rear wheel of my road bike up on a trainer and spin in front of the TV... my dorm's pretty tiny and the trainer is pretty noisey, but my roomie is a good sport! i should try those spivervals DVDs, though... watching Food Network is a bit masochistic (and not as productive), eh?
I also do yoga, weight training, and swimming... was thinking about trying out kick-boxing this year too. has anyone tried that?
some of the guys on my team ride through snow and ice-- no thanks! i'm afraid i'd hit a slick spot and wreck my ankle or knee, or worse- my bike!