“Photo sharing”: two words, quite a few meanings. And a lot of options if you want to share your photos. There are quite a few photo sharing websites. They don’t propose the same features. They don’t have the same objectives. Depending on what you are looking for, some will look much more aligned with your requirements than other. And you need to choose wisely as it takes time to upload your pictures and more important to build your community.
Don’t forget things can change quite fast: a newbie can become very hype; some services will shut down too. The main idea is just to give you a global view of these websites, the hot news and the trends from a personal, biased and non-exhaustive perspective.