I have the mirrycycle that mounts right on the shimano sti road levers. Works great, so far, although I think the mirror itself could be smaller.

My brother, who fancies himself a serious roadie, always finds himself endlessly amused by my cutout seat (it's a road seat, but clearly not a serious road seat!), the visor on my helmet (eek! how could I do such a thing!), the mirror on my bars, my kayaking gps that I use on the bike, the keen commuter spd sandals that work for my feet, etc etc. Whatever! I feel safer, and I get out and have fun 4 times a week, so who cares? It's a big brother's job to make fun of his little sister, even when we're both pushing 50 (plus, he's not really all that faster than I am).