If riding a Moulton is too mainstream for you, try the sideways bike.
I had seen these on TV but I was on my way home from work the other day, when I saw one of these being ridden by the inventor. I think he lives near my work place on Dublin's northside. He just seemed to glide along the footpath, moving through gaps in traffic, and managing to chat with enquisative kids with ease. Couldn't imagine doing Paris Brest Paris on it though...