SpoofCard - Disguise your Caller ID
Fake Caller ID - Fake Caller ID app provides users with a spoof caller id, and two free voice changer calls on a daily basis to make a call to their friends and pranks them in the voice of their girlfriend right at their fingertips.
Bad Numbers - A reverse telephone lookup of unwanted calls
Prank Dial - The #1 prank call site on the web!
6degrees - Get introductions through your friends' phones
Call Spoofer - Call Spoofer app helps users make a call on an unknown number by changing their caller Id, phone number, and voice to protect their privacy.