But having an HTML page for testing a browser is a bit tiresome when you want to test against multiple browsers, which is where JsTestDriver comes in. It's a jar file that lets you "capture" multiple browsers to a server which then runs your tests on all of the captured browsers. Designed for continual integration testing, I find it handy to quickly test all of my tests on multiple browsers while I am developing. Plus there is a QUnit adapter in their svn repository which lets me code in QUnit while running it simultaneously in multiple browsers when I am not actively debugging.
For testing the view of a web app I have found WebDriver works well. There you write Java code (icky I know, but you can use other JVM languages) which uses the Selenium Java bindings and launches browsers to test them. What's neat is that it simulates key input and mouse clicking, so if you use Firefox for the testing browser you can watch the test enter text as it runs (albeit rather quickly).