Clog, slip-on, sandal or otherwise, these guys tend to run in the same crowd.
What the Birkenstock indicates:
The Birk Man is a delicate creature. He's outdoorsy and simple. Can't be bothered by shoes with actual laces. Probably lives in fleeces year-round. Most likely politically apathetic beyond environmental issues sponsored by jam bands. Often accompanied by a woodsy musk, vegetarianism and an E.A.R.T.H. club membership. Dreading of the hair may occur. Will wear these shoes into the ground.
He'll probably get you to appreciate the simple things in life, like hiking and Dumpster-diving. May get you to R-E-C-Y-C-L-E. Lots of creative, free dates.