The AdventureCAM project started because we needed a way to hike and shoot video footage at the same time. We are constantly reworking this setup, but the basic configuration is pretty much the same (digital storage, remote camera, remote trigger, backpack).
http://www.rainydaymagazine.com/RDM2006/RainyDayProjects/BackpackCam/RDP_BackpackCam_Neuros.htm
An extensive insight view of how I transferred my old digital camera (which would probably fetch only $30 on ebay or such) into a infrared camera. The whole idea is just that a lot of people probably have old cameras laying around, collecting dust, so why not make one of your old cameras an infrared one?
http://geektechnique.org/index.php?id=254
The camera use for this experiment was a Sweex USB Webcam this camera was chosen for it's price and availability. As an added bonus, but nothing to do with this project, this camera works fine under Linux with a 2.6 Kernel (I'm using 2.6.8) using the sonixcam driver.
http://www.hoagieshouse.com/IR/