Last year, Alan Masarek made news as he left Google to become Vonage’s new CEO.
AnyWho - AT&T's Anywho service, fast and effective. Has map links.
Bigfoot - Bigfoot's People Search. Select the White Pages checkbox (default search is email). Simple search, but also gives names sounding "similar".
Infobel - Nationwide directory. fast and effective. Has map and direction links.
InfoSpace - Has feature to search a metro area or the region near a specified city. More of a search engine now.
InfoUSA - American Directory Assistance from InfoUSA. Can't do national search, state is required.
Switchboard - Another good national directory. Cluttered search page. Has neighborhood maps.
US Search - If you can't find it on a free telephone directory, US SEARCH is certainly the service that will find the information you are looking for. You will get an instant online report.
Whitepages.com - Nationwide search for people.
WhoWhere - Lycos WhoWhere people finder. Now under its own domain.
Yahoo - Yahoo's Telephone Search page. Has maps also, and email search.