Cactus?!

Phonelosers.org (archived link, may no longer work, try this one) has THE best prank call recordings I’ve ever heard. My two favorites have got to be Cactus (archived link, may no longer work, try this one) (Requires RealPlayer) and Harder and Longer (archived link, may no longer work, try this one) (Requires RealPlayer).

Not Safe for work - Language

The best stuff is here (archived link, may no longer work, try this one) and here (archived link, may no longer work, try this one) is their entire MP3 collection on MediaBuilder.com.