All you have to do is enter in the URL of your personal feed, and Spokeo will subscribe to your buddies' RSS feeds. Then you use Spokeo as the hub to see what's going on in your extended network. It's kind of like the Facebook "stories" feeds except it does a similar thing for all your networks. Cool idea, albeit possibly scary for some users. And as you may recall, the Facebook feeds experiment got off to a poor start.
Spokeo can subscribe to personal feeds from blogs and from services such as Flickr and YouTube. Nothing fancy about that, and if you're going to aggregate social network data, you might as well bring in the personal text and media as well. Spokeo also lets you recommend items, which will then bubble up on your Spokeo friends' pages, Digg-like.
The service is the product of a few Stanford students, and it could use some design work, as well as needing to be made simpler. There's good thinking here, but Spokeo is hardly the only RSS aggregator out there. I would not be surprised if other services (such as Netvibes) eventually built in special modules for handling social network data.
Also, Spokeo is read-only. If you want to interact with your community, you have to go to the originating sites to do so. And it doesn't work with all networks (such as Facebook, for example).
But in spite of the fact that it's not pretty--and that I'm not sure it's a sustainable business--it is a useful site. I signed up for it, and it immediately imported all the text and media from my friends' MySpace pages, and put it into a straightforward, if not fancy, format. That alone was a benefit.
(If you like stuff like this and feel the urge to grow your network, you might also want to try the new personals ad aggregator on Oodle.)