@Jeff - Awesome ideas - thanks!
The "relativity" of photo content is something I'm struggling with. On one hand, I don't want to dictate to people what photo content they should upload as long as it's legal and in keeping with the "family friendly" nature of our site. On the other, I don't want to water down our community with unrelated content.
I'll defintely have a "flag as inappropriate" feature so we find inappropriate content (ok... porn) quickly and delete it. I'm also thinking of a vote up/down kind of thing and tagging so people can easily find public photos they're interested in. But then we get into reuse-rights territory and public licenses, etc. (like flickr), so it gets complicated quickly.
I can't afford to give everyone gobs of storage space, but if the galleries become wildly popular, then we could always offer to let people pay for extra space. But I don't want it to be complicated... I just want to make it easy for people to share interesting theremin-related content with each other.
I'm often overly analytical, and I think this is one of those times :) Keep the ideas and feedback coming, and hopefully we'll converge on something simple and elegant and full-featured enough soon.