Just started playing with it, with my new found love of RSS I decide to join to see what the hubbub is about. Basically it's a photo gallery, but it's much more than that, notes and tags can be added to the photo's you upload, enabling people who are subscribed to certain tags to see you're photo's through an RSS reader.
Here's the photos I've currently uploaded:
http://www.flickr.com/photos/monkeyking/