Photophlow is the most exciting site I've found in a while. Back in the day, I used to use IRC chat, a really simple text-based chat client, to kick it with other random people on the internet. Photophlow is like a fancy IRC chat room customized for flickr users. Everything is tied to your Flickr ID, so you can look through your favorites, search flickr, or browse the photos of the other people in the room with you. It's not just text-based, either: you can post images for the whole room to see, and the entire interface is very graphical. Rooms can be associated with an existing flickr group, with a single person, or you can just make your own room.
If people actually use this, it could easily become one of the most productive online photo communities. There's a real possibility for discussion and criticism.
Check out the site! And drop by the Golden Half room if you do!
Also, I want to say this: productive online interaction should always be pointing towards something "in real life"—there is no point spending all your time behind a screen. I always hear about how great the Flickr community is, but I have the feeling that it takes too much effort to get anything out of the forum style of interaction that currently exists on the site. Chat is different; it's much more direct and much more human. Photophlow has the chance to create real-life communities, if for no other reason that that they'd necessarily take place in real time. That seems like a good starting point to turn a purely online interaction into a personal one.