(sharing this with a few lists I'm on) Others here might find this interesting: http://blog.mikemccandless.com/2011/03/your-test-cases-should-sometimes-fail.html
Lucene's test framework is pretty awesome. Lots of random stuff running something like 100 times per day on Jenkins. Not only that, but the framework is a standalone JAR. I'm not totally sure how we could bring it in, but the principals are really interesting. I've never seen anything like it and it has caught numerous bugs for us. -Grant
