I enjoy the Flickr community. I have never met any of my contacts but I feel like I know them and know some of what goes on in their life. Lots of good features and be sure to join some groups. I will say this don't join Flickr if you're worried about becoming popular...it will be great if it happens but more than likely it won't. Have fun!
Easy to use, interface careful & practical, many tools available, "Pro" account cheap and totally essential ! Cons: - The help & support for the French section is a disaster. - Support by email is catastrophic, because the answers are meaningless. - Lack of communication with the community.