You probably have an old processor lying around that you ended up modding into a keychain, but to take your geek cred to a whole new level, try wielding a blu-ray laser like a light saber the next time you fumble around for your house key.
Not only can it be done, but "jayrob," a DIY lasers expert, has posted a worklog of how he built his own using a keychain light made from a solid piece of brass that he picked up from Lowe's. In short, Jay stuffed a laser diode and a larger battery inside, did a little drilling, and ended up with the coolest keychain we've ever seen.
Read all about it here .
Image Credit: hacknmod.com