• Addresses.com Reverse Telephone Number Lookup
  
  Reverse telephone number lookup as well as some other specialized searches.
  http://phonenumbers.addresses.com/phone.php
• AnyWho Reverse Telephone Number Search
  
  Enter a telephone number and this database will return who owns it. From AT&T.
  http://www.anywho.com/rl.html
• Cell Phone Finder
  
  Contrary to the many websites on the Internet that boast about finding cell phone numbers, these numbers are not yet available to the public via a reverse directory search. You can find out if the phone number is from a cell phone by entering the number here and see what service provider the number is issued to.
  http://www.areadecoder.com/
• Directory Assistance +Plus - infoUSA 
  
  Over 103 million listings in this database available for public use.
  http://www.daplus.us/PhoneSearch.aspx
• InfoSpace Home & Business Reverse Telephone Directory
  
  Enter a phone number or address and this database will return who owns it.
  http://www.infospace.com/reverse.htm
• Internet 800 Toll Free Reverse Directory
  
  Reverse search for 800, 866, 877, and 888 toll free telephone numbers.
  http://inter800.com/
• PhoneNumber.com Reverse Telephone Number Search 
  
  Search for reverse telephone numbers.
  http://www.phonenumber.com/2321/reverse_phone
• Switchboard Reverse Directory Search
  
  Reverse telephone number search.
  http://www.switchboard.com/bin/cgirlookup.dll?MEM=1&QV=&LNK=3:3
• Verizon Home Reverse Telephone Number Lookup
  
  From Verizon's SuperPages.com.
  http://www22.verizon.com/utilities/reverselookup/
• Verizon Business Reverse Directory Lookup
  
  From Verizon's SuperPages.com.
  http://yellowpages.superpages.com/yp.advanced.jsp?&STYPE=AP
• Whitepages.com Reverse Telephone Number Lookup 
  
  Reverse telephone number search.
  http://www.whitepages.com/10001/reverse_phone
• WhoWhere? Reverse Telephone Number Lookup
  
  Variety of searches available to find who owns a certain telephone number.
  http://www.whowhere.lycos.com/
• 411.com Reverse Telephone Number Search 
  
  Reverse telephone number search.
  http://www.411.com/10744/reverse_phone

     See also, these cross-references:

• White Pages Telephone Directories
  
• Yellow Pages Business Directories
  

• People Finder  [ Gavel2Gavel.com ]
  
• Business Search  [ Gavel2Gavel.com ]
  
• Secretary of State Indexes  [ Gavel2Gavel.com ]
  

• Wireless Technology
  
• Free Ringtones for your Mobile Phone