I would wager that most of the people who know they need an SSH tunnel also know the Terminal commands to make it happen. But if those people happen to be Mac users, it's quite likely they wouldn't be averse to having menu bar access, Growl integration, Bonjour capability and a nice GUI to handle their tunnels. And to those who just know they want secure browsing, email and other network activities but aren't SSH ninjas, such things might be even more attractive.
Code Sorcery Workshop's Meerkat is a handy application that provides all of the above tools and offers setup wizards to provide the right settings for the particular tunnel you need. It turns setting up a quick SOCKS proxy for web browsing into a 2 minute task. Setting up a tunnel for Mail is just as simple. Whether you're already using tunnels or looking to get some protection while browsing at the coffeehouse, Meerkat may be able to help out.
You can try Meerkat out for free with a time-limited demo. If it should become something you can't (or don't want to) live without, you can register it for $19.95.