I'm a pretty big Flickr user, but out of all the online services I've used, it is one of the most un-innovative. Very little has changed since I signed up for Pro 2 years ago. Given Yahoo's other problems, this is only a sign for the worse.
If you are looking to just host your own and don't feel the need to directly interact in a community, OpenPhoto looks really interesting: http://theopenphotoproject.org/.
I've thought about rolling my own and using it as an opportunity to learn rails, because these things are so simple to do nowadays, but OpenPhoto looks like an interesting offering.
