It's interesting - people think because so-and-so owns a Leica/Nikon/Canon/'Blad etc, they are a good photographer. And on the converse that if they only have a cell phone camera, they necessarily cannot take good photos.
It's so much about the eye rather than the tools. Here are some of my favorite photos taken with an iPhone.
Véspera de feriado em São Paulo (via Marco_Y)
international (via di_jo)
And here are some of mine favorites that I've taken with an iPhone
They say the best camera is the one you have with you. Nowadays with the iPhone (and android) you can not only take photos, but use really fantastic filter and manipulation aps (I'm a fan of instagram, colorblast, filterstorm, photoshop, and tinyplanet myself)