Sadly, we do not have as much regression testing over our medical software as we would like. We have used Test Complete by SmartBear in the past, but for any UI testing done now, we just use Coded UI tests from within the Visual Studio Test System. I would probably stick to one of these.
We will be releasing the test tools with SFv2 (when it finally hits
) that are used for regression testing the UI of SF. It's got a test harness and an injector that allow you to inject the test DLL into your application while it's running and launch the tests on a new thread of the application. Right now it's all hand coded, but it doesn't take long to create one.