I've been in love with fixies for a while now and maybe this summer I'll be brave enough to try riding one on the hills of Vancouver. Fixies, otherwise known of fixed gear bicycles, have only one gear and sometimes no brakes. they're loved by fixie riders for their minimalistic, clean lines and a closer feel to the ground and terrain.
I particularly love these cycles from Mission Bicycles from San Francisco - pictures below are from their Flickr gallery.
Fixie fashion is also uniquely chic - they're the cool boys and girls you see whizzing around main street with their newsboy caps, rolled up denims, messenger bags and checkered Vans. The panty shorts below might be a traffic stopper though.