Folders, recumbents, tandems, and fixed gears (and even folding recumbent tandem fixed gears!) certainly are not the norm, but, in reality, they're not all that odd either. If you get ribbed by your friends for riding whatever odd human powered contraption you're riding, give them these ideas to consider:

C.H.U.N.K. 666
S.C.U.L.
Atomic Zombie
BikeRod & Kustom
Conference Bike
Penn State Six Pack
Marathon Rock Band on Couch Bike
Amphibious Bike
Couch Bike at Critical Mass
Couchbike
Hula Bike
Treadmill Bike
Homebuilder's Gallery
Bike Kill 2005
Carbon Fiber/Bamboo bike
Bicycle Record Player
Velo Vision and Encycleopedia often feature freaky cycles, too.

All this goes to show, that there is no reason to ride a "normal" bike. So if you're afraid of looking weird, don't be! Be proud of your uniqueness. And if that's not enough justification to ride your freakish bicycle, keep in mind there's always someone freakier!