So how many social networks do you belong too? Two? Five? More?

Chances are there are wrinkles and differences to the personal information you provide on each -- say, MySpace versus LinkedIn. A Silicon Valley startup collects information from public data on more than 30 social networking sites, including Flickr, LinkedIn, MySpace, StumbleUpon, Windows Live Spaces and YouTube. With a Spokeo  account you can add friends, or anyone else for that matter, by email or their profile URL, and the site collects their information from the social networks they belong to.

Each time you log in to Spokeo you'll get a summary of changes made by your friends,  or any other folks your tracking, at these sites. Spokeo calls its service, which only collects information that is public on these sites, a "Friend Tracker." 

A blog entry by Spokeo's founder Harrison, begins: "Whenever I introduce Spokeo to my friends, their first reactions are always "Wow!", then "Hm ... this is a little scary", then "This is freaking cool!".