The Open Bitcoin ATM claims is “the worlds first open-source automated teller machine for education and experimentation.” (I suppose they beat Skyhook to the punch?)
The website includes a step by step tutorial to build one, and states that the cost of components is less than $500. It appears to do BTC for cash, but doesn’t dispense cash for BTC.
We also have this sweet demo:
Website: http://openbitcoinatm.wordpress.com/
Source: https://github.com/mayosmith/openbitcoinatm