The cell phone gps tracker has an entire website dedicated to it. You communicate with the device by sending text messages and can get all the data you'd ever need from it about your location, speed..etc, all with a cheap prepaid cell phone. Be sure to take a look.
This project write-up offers the fundamental details about the old school nokia cell phones. The main focus of the write-up is modifying the LCD so that we can write whatever we want onto it. Hardware schematics & software are there for you to download.
As if a standard ir remote control wasn't good enough now you can use an SMS message to control your VCR. This project utilizes SMS technology & a PIC microcontroller to tell your vcr what to do. Press record from thousands of kilometers/miles away!