If you’re looking for a place to learn about street photography online, I believe the only real group that is worth looking at is Street Fight on Flickr.
What is the group?
You can see in the discussion tab different matches where two photographer’s work that contains similar characteristics are matched against each other and the community votes on which photograph should be entered into the pool.
It’s a good place to learn and determine what makes or breaks a strong street photo. If you’re looking for a place to see contemporary work online or a place to participate in discussion, this is one of the only places I suggest going to. Oftentimes people ask me where to see work online, so I figured I suggest this group here in this quick blog post. Maybe this resource could help one other person!