Thumbz is a photo sharing app for your Windows Phone that allows you to... well... share and get feedback on your photos. Once uploaded to the network, other members can vote up, down on your photo as well as leave a comment. You in turn can rate and comment on others photos as well. You can also use Thumbz as a informal public opinion poll if you include a question in the image description.
Thumbz does have a novelty feel to it but it also has the potential to be a decent photo sharing network. It just needs time and to see it's membership continue to grow.