I heard about Phanfare, several months back and knew that it was a very cool use of the .NET Framework -- but until I started using it recently it never occurred to me just how well done it is. With ASP.NET on the back end driving the website and a Smart Client application for managing/uploading photos it makes photo sharing easier and more fun then anything else I've ever seen or used. I know I sound like an ad, but trust me this completely on my own -- it is cheap, fast, and provides unlimited storage. I think they really nailed the formula and it really excites me that ASP.NET and the .NET Framework were the technologies that enabled them to do it.
Check out Phanfare at http://www.phanfare.com/
Read about it on CNET (they agree with me =) ) http://reviews.cnet.com/4520-6451_7-6245143-1.html
curious to hear your thoughts/experiences.