PeekYou

... calls itself "a new kind of online white pages":

A PeekYou profile helps other people find your websites, social-networking pages, photos, or anything else about you online. You can also create a profile for friends or relatives to ensure that they may also be easily found online.

The site claims to have more than 50 million profiles, although most I looked at randomly were pretty bare. Two potentially useful features: You can search by online user name, and you can narrow your search results by country, state and town.