Tidepool lets you collect, organize, describe, and browse your personal memories, such as digital photographs, movies, sound clips, and stories. With Tidepool, you can tell the who, what, where, and, when of it, using semantic web tagging technology. Big Fractal Tangle: Tidepool
I'm not sure what the name for this category of applications should be. I guess "life log" is as good a name as any. I've seen the name used elsewhere, but Google is not coming up with anything authoritative (well, there is the Pentagon thing, but I was thinking of Nokia's Lifeblog).
So many companies are swooping into this space because they see a real pain: it's hard to get all this stuff done right and done easy. People will pay money to have the process of sharing pictures, etc. made easier. This is why Apple has been successful: they've made all these areas pretty much push-button simple.
But this is a very hard space to succeed in. Usability and reliability are two huge factors, both of which are deeply tied to the operating system. Apparently, Tidepool is being delivered with Java Web Start. I personally like this technology, but I don't know how easy this is going to be for people to use. I'll reserve judgement until I get a chance to use it myself.