Low Budget Air Space Photography
An anonymous reader writes "With a budget of just 350 pounds, two British PhDs in engineering sent a balloon with cameras attached to a height of over 30 km." The photos and video are pretty amazing. Especially the very hi-tech styrofoam box.
In the US, the FAA has rules for untethered balloons. If you're below certain size and material restrictions, you're good to go. Issuing a NOTAM (Notice To Airmen) is highly recommended, even if you're not required to file one. Demonstrates that you're being professional about your activities.