Since most people carry a USB memory stick around with them these days, especially geeky sorts who want controlled access to computer lab, why not take advantage of the stick's unique serial number to act as a key? That's the theory behind this Makers Local 256 project, which monitors new USB devices plugged into an external reader, checks them against a list of approved keys and, if found, unlocks the door. [note: Certificate warning on link appears to be benign]
Check out the demo video of the USB-controlled door lock after the cut
No data on the memory stick itself is actually used, or accessed, so it requires no space. There's also a magnetic sensor which stops the bolt from shooting when the door is open, and they're planning a mechanical override for use in power-cuts and emergencies.
The project cost around $60 to put together, and ongoing costs would be far lower than commercial electronic access systems. Rather than having to buy proprietary key blanks, inexpensive USB keys can be used; alternatively, a visitor's own memory stick could be added to the approved list. One less thing to forget.
[via Hack a Day]