Johnnyoptic's DIY tilt lenses
I'm infatuated with Johnnyoptics beautifully built DIY tilt lenses. Here are four of his creations; the front middle and front right are built using a bike inner tube as the rubber coupling. I'm particularly fond of the middle front one - Rubber Ducky, a 28mm f2.8 jobbie.
A complete gallery of his tilt lenses can be found here.