Everybody loves their webcams (though the surveillance aspects of some are to be worried about.)
What about a way to make them cheap and easy to put in cool places. Combine a webcam with a solar panel, 802.11 link and small bettery. The webcam charges the battery off the panel, and when there is enough charge to take a picture, it takes one and spits it out the wireless link. You don't need much of a battery or much of a solar panel, because the amount of power simply controls how often it can take a picture.