I currently own a 28" Univega mountian bike, which I bought on my mission. I enjoy riding immensly, but do not have much time to do so. I am planning on riding to/from work on a daily basis when it gets a little warmer, hopefully by the end of April. The trip is only about 8 miles, and takes about half an hour, if traffic doesn't get too much in the way. There is a park nearby which affords some great riding trails.
April, 2000 Update-
Well, I did very little riding last year. I've also moved, and my wife and I had our first child. I am now only 4 miles from work, and have no excuse to not ride my bike to/from work. With the gas prices up, I've figured in the cost of the car, insurance and maintenance, and it looks like the car costs about $0.20 per mile to use! This means it is actually less expensive to buy a bus ticket ($0.75) for each direction than it is to drive myself. This is costing me about $32/month. I could instead spend that money on a fitness club membership, and get in shape. But wait! If I ride my bike, then I'll become more fit, and still save $32/month!
At least, that's what I keep telling myself. Not only that, but my company is moving about 1/2 mile closer to my home. I have no reason not to bike, once I get in shape it'll take about the same amount of time to bike as it does to drive (15-20 minutes). Well, it'll happen someday....