This is well worth a look if you use a Cisco VPN. The client Cisco provides is a command-line tool. VPNConnect provides a nice Aqua interface to it so you don't need to bring up or even see the Terminal. Not complete yet, but already very nice.
[Editor's note: I don't have a Cisco VPN to test this on, and I can't seem to locate the 'real' web page, so the above VersionTracker link will have to do. The comments there seem to indicate that this is a nicely functional program.]
Mac OS X Hints
http://hints.macworld.com/article.php?story=2002031801360463