"The best camera is the one that's with you," writes Chase Jarvis (hmmm, where I have heard that before!). He takes photos everyday with his iPhone, processes them on the device, then shares online. Chase maintains a gallery of his favorites on his site.
There is so much good work you can do with these types of devices: iPhone, Nokia, Blackberry, Sony, and on and on. I think mindset has much to do with success. Take a look at Chase's work, and you'll see what I mean.
iPhone App Reviews and Camera Phone Tips