My new project is up and running at www.wysiap.com! Here you may ask and answer the question, "Would you superpower if arbitrary penalty?" You choose the superpower and the penalty. The goal is to come up with a superpower and penalty so evenly balanced that it's impossible to say yes or no.
I started this project primarily to learn Groovy and Grails, and I've been more-than-pleasantly surprised at just how awesome it is to work with! Groovy eliminates a lot of Java's verbosity, and Grails conventions and plugins make development much faster. Plus, it's still possible to fall back on Java and it's many libraries if necessary.