David Brin might be interested in finding developers looking for an open source project. Here's the link to his blog entry.
And here's the gist of the idea:
During natural disasters like Katrina, the cell phone network went kaput. He'd like to have cell phones able to send text messages (not voice) peer-to-peer, bypassing the cell towers, at least during emergencies.
I think it could be done as a proof of concept project in two stages.
First, use plain old networked computers to develop the protocol and routing stack so they'd spontaneously organize into a network and allow simple text messaging. The challenges will be keeping the routing traffic under control, even if the network scales to hundreds of thousands of nodes, and keeping the routing tables small enough to fit in a phone's very limited memory. These are not trivial problems, but major street cred, and probably some publications, goes to anyone who can crack them. Personally, I'd suggest sacrificing low latency and the ability to text while the phone's moving.
Second, port it to the Green Phone (Trolltech's open source phone) to see if it works there and to get a handle on power consumption.