Fellow blogger, James of The Urban Country, has produced a nifty little site called Rate My Vélo. Post a photo of a bike, someone riding a bike, or just looking good near a bike, and subject it to intense voting from the critical citizenry.
Rate My Vélo show pairs of photos seemingly randomly (though there isn't a large database just yet). One then simply clicks on the photo they prefer out of the pair. And then one is presented with another pair and so on. After one gets bored with that, one can look at the most popular photos (currently heavily favoured towards chic chicks on bikes).