Tunnelblick is a ready-to-use graphical OpenVPN client for Mac OS X. It comes as an application package with all binaries and drivers included, no manual installation necessary.

It works on Mac OS X 10.4 (Tiger) and above. Fixes to the recent compatibility problems with Leopard are included in the latest snapshot and are currently in the testing phase.

If you want to discuss issues, there is a wiki and a discussion group.

Thanks to Mjam for the good food