I have a Treo 600 - it’s not exactly a camera phone as much as a Palm PDA that just happens to have a phone and camera built in - the camera is only VGA res, but it takes about the best quality VGA snaps I’ve seen - they aren’t any good for any kind of serious photograph, but they are useful for:
Snapping a quick picture of an address/map/phone number, instead of manually transcribing it from a poster or flyer
Taking pictures as evidence that something or other happened, or that you actually went to such and such a place
Electronic holiday postcards (I snapped one of myself and the family on the beach, attached it to a bit of waffle in an email and sent it to the folks at work right there and then)
Mobile webcam - I’ve got an FTP app, so (in theory - I haven’t tested it yet) I should be able to update a photographic blog/journal while out and about, or update a webcam from a concert or other such outdoor event.