Our space-grant group has done projects similar to that, they send payloads up on weather balloons. It's a great low-cost way to do awesome stuff. Though technically that legoman didn't make it to space. 75000 feet is only 14-15 miles while the US "official" boarder to space is 50 miles, the ESA's definition is 100 km which is 62 miles.
On an unrelated note, I happened to sit next to an official from the Canadian space agency on a plane flight. He was a pretty interesting person to talk to.
