Cell phones are easy enough to come by these days, but if you've ever wanted to just build your own, Instructables user xiaobo__ shows how to do it with an Arduino.

The little DIY phone isn't cheap by any means, but it's still a phone you can build entirely yourself, which is great if you're not into those new upgrade plans the carrier's are offering. The system uses an Arduino, a touch shield, GPRS shield, and a few other components. Then, it's as easy as clicking everything together, loading up the code into the Arduino, and making your first call. It's actually a pretty easy process in the end, and you'll certainly be the only person at the party with a phone you built with your own hands. Head over to Instructables for the full guide.

ArduinoPhone | Instructables