OK, my headline is harsh. The Experience Project is actually a very good social network play. It's all about life experiences, and it's designed around anonymity.
What's the point of hiding yourself in a social network? Say you're battling an illness, or trying to improve yourself in some way, or are struggling with an emotional issue, and you don't exactly want to share it with the world. You might not want to put "I'm fighting depression" in your public MySpace profile, but you might well want to talk it through with other people in a similar boat. The Experience Project lets you find these people and share stories. It's an online, general-purpose support group site than can be used for very specific topics.
Not all Experience Project experiences are negative. You can also read and post stories about singing karaoke, falling in love, or adoring Stephen Colbert. Once you have identified yourself through your stories, you can find the people most similar to you--those who share similar stories.
My criticism of the Experience Project centers on its user interface: stories are sorted around free-form headlines. There are several stories, for example, entitled, "I battle depression," but if you answer the site's front-page question to tell your story and you type in something slightly different, such as, "I fight depression," it will create a new group with you as the only member. If you search for "depression," though, you'll quickly find the relevant groups.
Overall I think this is a strong and useful service. That's in large part due to my view that it makes sense for people to identify themselves by what they've done, much more than by what they've bought, as Zebo does. Yet the Experience Project is not likely to become a general-purpose social network, since it has such a laser-focus on protecting identity (you can even have it blur the pictures you post). But it could be a good tool for people to use in addition to a typical social net like MySpace or FaceBook.