LEGO-master Ronald McCrae’s incredible Brick Bank ATM can accept an ATM card and store account balances in its internal customer database. Just like the real thing, it can check for a correct PIN number, and hold onto your card if you enter the wrong number more than three times. It can even make change from paper money, and be calibrated to accept any currency.
Amazingly, this thing is almost entirely constructed from off-the-shelf LEGO bits. Ronald only added a HiTechnic IRLink and a Codatex RFID sensor to read the ATM cards. Funny thing is, I trust this ATM with my money much more than the ones that run on Windows.