InfoSpace, is an easy-to-use tool for finding people online. Along with searching for phone numbers and email addresses, InfoSpace can run reverse lookups — finding a person's name using his or her phone number, email address, or physical address.

Four11 is one of the older directories online, and its listings are updated frequently.

Four11 is owned by the Yahoo! search engine, so it does a good job of finding links to people's personal Web pages. WhoWhere? offers a very clean, simple interface for finding email addresses and phone numbers.

WhoWhere? also lets you run advanced searches based on a person's location. Bigfoot can do phone, email, and Web searches (powered by the LookSmart search engine), but its email addresses aren't as updated as some of the other directories.

If you can't find an address in other places — especially if you know that the person has had this address for several years — Bigfoot may have it.

Finding addresses with search engines
Almost every major search engine now includes an email lookup function. Generally, the search engines do not maintain their own email directories, so these links connect you to Four11, WhoWhere?, or other online directories.

Keep trying
It's important to note that there is no central database of information about every single person. Some of these databases may include people the others omit, and some may be more up-to-date than others. If your search is unsuccessful with one of these resources, try again using another.