WorldPages--individuals, businesses or business type in U.S. and Canada. You can limit city/state/province/postal code. Very fast and you can create a map of an address' vicinity
AnyWho Toll-Free Directory--search by business name or category, browse by category. Also includes reverse lookup and e-mail lookup. Formerly the AT&T Directory
Internet 800 Directory--"hundreds of thousands" or 800 and 888 listings, including all carriers. Search by name, product or number
Bigfoot--white page, e-mail and yellow page search. You can also search on a first name in a city though results seem incomplete
InfoSpace--112 million listings in U.S. Yellow pages, white pages, companies online, classifieds, federal/state/local government listings with councils' members and phone numbers
GTE/Verizon SuperPages--nationwide yellow and white pages. Click on Detailed Search for reverse lookup. The former BigYellow address now goes to this site
Switchboard--nationwide residential, business and e-mail search
Questdex Yellow & White Pages--formerly U.S. West. Quite useful for searching a business category in a city or state. Other features include reverse search (click on Advanced Search) and community links by city. Oh, they want you to register now
The Ultimate White Pages--actually a one-site location for the other national phonebooks; search by name or phone number
Fonefinder--an odd reverse directory that allows you to input area code, prefix and city for U.S.; otherwise, whole telephone number and country name. Doesn't get to individual name level, but uses could include listing possible prefixes for a given area, and what telecom company services them
Trackem--Rich Reen has consolidated a number of telephone and e-mail search tools on this page
World's Phonebooks--every nation possible, although most smaller ones sport a fax directory only
Infobel International Directories--directory of international directories. Many are fax or trade directories. You must first select a country from the pull-down menu
International: North and South America
Seccion Amarilla-Indice--Mexican yellow pages, with link to white pages also. Yellow pages also have English version
Canada 411--search for individuals or businesses in English or French
Yellow.ca--Canadian business pages, search by business name or classification. Also includes search for individuals, or reverse lookup
Caribbean Telephone Directory--separate directories for the various nations and island principalities. Search is by name only. The directories have varying update schedules
Costa Rica In-Focus--Costa Rican telephone book, individuals and businesses by name
Lista Telefonica--links to phone books for various states in Brazil, in Portuguese. Centralization appears to lie far in the future
Paginas Doradas--yellow pages for Argentina, searchable by business name or type
1BillionIndians.com--but how many have telephones? Likeable interface allows search for individuals with options for nickname, family/friends, schools/colleges/workplace, and limiters for age and sex!
China Big--quite efficient yellow pages for China, searchable by company name or business type, with full names and addresses given. English version available via upper right corner
Townpage: Japan Telephone Directory--English version of Japanese yellow pages, searchable by company name or business type. For Japanese version, chop English off the URL
Israel's Yellow Pages--this site is an umbrella for several directories, none well explained. Complete Israeli Yellow Pages is in Hebrew. The Internet Israeli Yellow Pages is in English but is much less comprehensive
Bezeq 144--Israeli directory. You'll likely have to accept download of software to read characters
Specialized
Reverse Directory via Langenberg.com--or actually, links to various services' reverse lookups, by address and/or phone number. R! means clear or reset
Pay Phone Directory--thousands of payphone numbers listed by state/city/address. Greatest number are in Washington, since that's where "El Jefe" apparently resides; a good many for Oregon also