I gave a presentation on Spock a very nice BDD framework in Groovy a few months back to our Groovy Users Group in Sacramento. After using it on a real world Grails project the last few months it has grown on me to become my go to testing framework for Groovy/Grails or Java projects. A typical specification looks something like this:
If that passed your 5 second test take a look at a fuller introductory tutorial I put together.
And if you want to try out executing real code the project has a nice browser based environment at Meet Spock.