High-Altitude Balloon

[shepting]

I heard there might be some interest in doing a High-Altitude Balloon group project.

I've got some weather balloons (officially expired, but likely still fine), a VX-3R handheld ham radio for APRS positioning, and a throwaway digital camera (Canon SD450 with broken display) for pictures.

I would love to get involved if there are some other guys interested in doing this.

[SubterraneanZen]

What size are you balloons? I've been working on putting a rig together and i estimate we would need a 600g weather balloon to achieve 75,000 ft with the gear i've been looking at. The sd540 is a good size but we would have to wire an external intervalometer to it as it doesn't have that feature built in. I've been looking for cheap HD gopro cams, they're small and only weigh about 127g + an extra battery. the VX-3R at 130g would be real easy to work into a rig.
What are you thoughts on a rig?