Carburetors! One of the guys in my office is into 1930's Packards, and had these running on his car on a homemade manifold about 20 years ago. He saw my calendar, recognized the 97's on a few cars, and asked if I wanted a couple. I came into work today, and they were sitting on my desk. They weren't free, but closer to it than I expected...
Well, I did give him five $20 bills, which beats the hell out of free coffee! And psychodaemon, you're right--that calendar investment has certainly paid off.