v 1.2|PeerBlock, LLC
PeerBlock allows you to control who your computer "talks" to on the Internet. You can block communication from spyware-oriented servers, monitors of your p2p activities, hackers, and other "known bad" computers by creating appropriate lists.
They won't be able to get into your computer and your computer will not attempt to send them anything.
It's also free!
PeerBlock is an extension of PeerGuardian.