I think they're not so great as communication devices, rather than finding new people interested in the same things. It's really a way to just put yourself out there - all in one page, a summary of you for viewing. It tells a lot about people, but I still like messageboards better, because there's a lot more talking. I would find it much more interesting, however, if UM had a profile directory! now that would be nifty. having messageboards + facebook/myspace at once, in one cohesive site, would be awesome.