This page describes technologies that can be used for a near-space balloon launch.

Camera/Imaging

Canon Powershot

Using the CHDK project, you can run arbitrary software on the camera's CPU. Project Icarus used CHDK to disable the LCD display and loop, taking a picture every 5 seconds.

The cheapest new Powershot is $150, but these models haven't been ported yet. The cheapest supported Powershot (new) is $270 from Best Buy (which is too much). A more practical option is to find a cheap used Powershot.

Benefits: no microcontroller required, high quality images
Drawbacks: cost

Cheap camcorder

dealextreme.com has cheap digital camcorders (no lcd display or other frills) for $50-$70.

http://www.dealextreme.com/details.dx/sku.31878
Cost: $55
Mass: 296 grams

Benefits: no microcontroller required, video
Drawbacks: image quality of stills

"Real" camcorder

http://accessories.dell.com/sna/products/Camcorders/productdetail.aspx?c=ca&l=en&s=dhs&cs=cadhs1&sku=A2612051
US $120 Kodak ZX1 HD camcorder
Benefits: decent picture, video (get what you pay for)

Cheap camera, disassembled

We take a cheap camera, like Gus's $25 camera, take it apart, and hook up some simple electronics to take a picture each 5 seconds.

Benefits: low mass (strip stuff we don't need), can separate lens/ccd from electronics for heat management
Drawbacks: extra electronics work, crappy resolution (300K pixels? -- you get what you pay for)

Cell phone

If we are going to include a cell phone anyway, maybe we can use its camera. I think this only works if we can load our own software into the cell phone. Eg, like an Android based cell phone.

Drawbacks: cost

Batteries

Lithium Photo (Lithium / Manganese Dioxide)

Non-rechargeable, 3V.
Operating Temperature: -40C to 60C
Energizer "123" $10 1500mAh 16.5g Specs: http://data.energizer.com/PDFs/123.pdf

Lithium Polymer