Last night at the RubyJax meeting I was pair programming with one of the fine folks at Hashrocket and he turned me on to rspactor. It is a gem that automatically and continuously runs your rspec tests and alerts you to failures as you code. It is very lightweight easy to use. All you do is execute rspactor from your project root and off it goes. It runs your whole suite of tests to get started and then any tests that are impacted by the work you are doing as you go. There are a few other tools similar to this one. If you aren't already using one, I would highly recommend checking this out. http://rubyphunk.com/2008/3/11/hello-world-introducing-rspactor