Looking for the relative you haven't seen in years, or that long-lost high school sweetheart? Here are the most popular people search sites to get you started. Most also have links to Yellow Pages listings, online maps, and often offer free e-mail.

Bigfoot - Bigfoot has a huge collection of e-mail addresses and white-page listings, and features a simple interface, security features, and an aliasing feature that lets you keep a stable e-mail address regardless of your Internet service provider.

Infospace - Billed as the Ultimate Directory, Infospace searches for phone numbers, e-mail, addresses and much more. Features reverse lookup and a celebrity search.

Internet @ddress finder - IAF is especially strong at finding university e-mail addresses, and AOL and CompuServe subscribers. If you know that person's name and other information about that person, such as the company or organization they work for, they may be among the over 6 million listed.

Lycos People Search - Featuring an impressive collection of personal home pages and security features, this e-mail-address, telephone-number, and mailing-address finder also has links to other search services such as apartments and job listings.

Switchboard - Perhaps the oldest online directory, you can search for people, businesses, web pages and e-mail. Search by name, city, state or affiliation.

Worldpages - Offering yellow and white page listings, over 230 wordwide directories (in over 30 countries) #12; e-mail and website searches.

The Ultimate White Pages - The Ultimate White Pages is a centralized, fast, and common interface to most, if not all, the white pages listings.

Yahoo People Search - features  e-mail and telephone-number searching, and useful filter options like specifying the name of a high school or college.