Caller ID by WhitePages - $6.99

Caller ID by WhitePages is a new application for the T-Mobile G1 Android phone. Users can find out who’s calling, instantly. Caller ID by WhitePages will search 200 million U.S. listings and display the results in seconds (even info on mobile users can be found using their service). Users will get a notification of the Caller ID call, and can then have the option of adding that person to their contacts or viewing a map of their location.

Other features with this paid version include:

• Telemarketing alerts - will flash during calls from known telemarketers.
  
• Reverse Phone Look up - users can now look up phone numbers to see who they originate from.

More information can be found at http://blog.whitepages.com/