Working nights and getting home late, I sometimes find it hard to sleep. I've taken to putting my yoga mat out next to my bed before I go to work. When I get home, instead of sitting on the couch watching TV until I'm tired enough to sleep, I get in a quick yoga session. Stretches me out, relaxes me after a long night, and gets me ready to sleep.
My favorite Yoga DVD's to do are PM Yoga and Power Yoga for Flexibility, both available from Gaiam, featuring Rodney Yee.