Creating A Tiny, Free, Roaming Webcam?

vitus979 asks: "Every year there is a big 7 day bicycle ride in Iowa called RAGBRAI (Register's Annual Great Bike Ride Across Iowa), and an interesting problem was put in front of me and I'm looking for the best solution: make an extremely lightweight, self-contained webcam system fully independent of a base station, but yet able to upload pics to a file server from nearly any location in the state of Iowa to be shown on a website in realtime."

"I thought it would be cool to mount a webcam on my bike when I go this July. I looked around on the web and the only similar implementations I could find included a bike trailer and 20lbs worth of computer parts. I know that a person can do better than that. I'll be at least 5 miles from a support van at any time so short range solutions (Bluetooth, 2.4ghz wireless LAN) isn't an option unfortunately. What I'm looking into is a small webcam linked to a PDA with a cellular modem. The webcam takes pictures every couple of minutes and the PDA takes the image, calls on the cell modem, uploads the pic, and disconnects the call. This saves me cellular charges and conserves power so that I don't have to carry a bunch of batteries with me.

Basically I've gotten to the point that I need a firm set of hardware and a good wireless implementation to get the information to the servers. Below is what I will need for the system. Any suggestions for each piece, or a full working system that could be purchased would be very helpful.

Webcam: the smaller and more power efficient the better, something all weather, the size and shape of a pen would be optimal since aerodynamics play a part in this piece and I don't want something like a Logitech QuickCam stuck to my helmet.

Computer: PDA sized or smaller if possible. Needs to be able to connect to both a Webcam and a Cellular Modem and be able to do the work explained above. As power efficient as possible, the longest lasting batteries possible. Needs to fit in bicycling jersey pocket (about 4 inches wide and 8 inches deep).

Modem: this is problematic as not all of Iowa is covered for digital cellular service but all of Iowa IS covered for analog at least. Another option may be the recently reinstated Iridium system (I read somewhere they allowed data transfers)."