Enter Meerkat, the SSH tunnel tool with the friendly face. I mentioned Meerkat about a year ago, and apparently things have been busy at the Code Sorcery Workshop since that release. The latest version of Meerkat -- version 1.2 -- sports an array of new features, from AppleScript support to a command line utility, as well as improvements to existing features like Bonjour sharing and the tunnel editing interface. I've been using the previous version for quite some time now, and I can say that this version adds some great features to an already great application.
AppleScript support means automation, and Meerkat plays well with location managers like NetworkLocation (a plugin is available on the Meerkat page), or any location manager which can run AppleScripts or shell commands. With such a setup, you can have your system automatically detect a change in networks and set up specific tunnels depending on your location. I won't go into the details of location managers right now, but it's something to look into for laptop owners on-the-move.
Additional features, including Application Triggers, Bonjour support and automatic reconnect for dropped tunnels all make Meerkat a valuable tool. At a current price of $19.95US, Meerkat provides features for a spectrum of users, from the Tunnel Setup Assistant for newbies, to advanced automation possibilities for veteran SSH'ers. I'd be negligent if I didn't mention at least one similar app in the freeware realm: SSHTunnel is a nice, easy-to-use GUI for setting up and managing tunnels. It lacks some of the automation and integration capabilities, but is a definite must-see if you're not ready to fork out for something more full-featured.
A trial of Meerkat is available for download, and a license can be purchased for $19.95US.