A group of MIT students did a high altitude balloon launch. That’s really not all that unusual: radio amateurs do similar launches several times per year. What is unusual is the price tag: $150 total. They used an inexpensive Canon camera running the CHDK firmware to snap images, and a cheap no-contract Motorola phone to communicate coordinates back. It’s not the greatest engineering choice really: the cell phone lost contact after gaining only 2500 feet in altitude, but it is a pretty interesting idea. They managed to do just about the minimum possible and still create a recoverable high altitude payload. There was no custom hardware at all. Check it out: