I find that I don't have a lot of time to ride for fun (not that there's a lot of fun to be had out London way), but I do have to go to work everyday. That's why I commute on my bike. Straight lines are a little more tolerable to me on a bike. I've also got enough luggage that I can stop for groceries or whatever on my way home. I actually tend to use my bike for almost everything but "fun" rides.