My 15 year old daughter, for whom I bought two used beach cruisers so we could ride together when she's at my place, now simply REFUSES to walk for any errand in the neighborhood, be it picking up some dinner, getting a video, etc. Even if it's just a block, we have to ride the bikes. And of course, take a long route. Nowadays she looks for an excuse for us to run an errand, even after we've had a few miles of pure recreational riding.
I'm a lucky guy and a happy dad!