Tesly Jr. (http://junior.tesly.com) is a hosted web app that provides an HTML reporter for your unit tests. With an RSS feed that gets updated with your test results every time you run your tests, it’s great for continuous integration. The web interface to your test results also helps to prove that you’re actually running tests.
It’s free and easy. Set up an account, download and configure the Rails plugin, and be amazed as lovely green bars show up on the web as you run your tests.