Description:
Platform Support:PeerGuardian 2 is Phoenix Labs’ premier IP blocker for Windows. PeerGuardian 2 integrates support for multiple lists, list editing, automatic updates, and blocking all of IPv4 (TCP, UDP, ICMP, etc), making it the safest and easiest way to protect your privacy on P2P.
... and they have it for OS X, too.PeerGuardian 2 supports Windows 98, ME, 2000, XP, and 2003, in 32-bit and 64-bit.
Note: PeerGuardian 2 does not support Windows Vista at the moment. This is a top priority, and we hope to have a Vista download soon.
Portability:
Settings and lists are stored in the application folder.
You can also use local lists, and I noticed that PG2 uses a relative path if the list is stored at the same drive.
License: Open Source
Get it here: http://phoenixlabs.org/pg2/ (Use Universal Extractor)
(There is also PeerGuardian Lite, which I haven't checked out yet. It is a derivative of PeerGuardian 2 made to consume as little CPU/RAM as possible. It has no UI or options and consists of a single tray icon.)