It's got a simple, easy to use design. Touch Mouse is a very slick way to control the home entertainment computer, without getting off the couch (Netflix anyone?).
It's a lot like Apple's iTune Remote in that it shows what a powerful, integrated remote control program can do, if you're willing to be specific for a single application.
Both of these programs require you to run Apple Bonjour on your PC (which you are if you installed iTunes at any point), and to install a small program on your PC to act as a middleman. Instructions for each can be found after you find them in the iTunes store.
The half of our staff that didn't have iPhones have all purchased new Droid phones in the last two weeks, so I will be moving on to taking a good look at what Android + Connectify can do for you next. If you're already using them together, please drop a comment and tell me how.