A while back we were starting a large J2EE project with some folks that had not spent a lot of time with the Java language. One of the things I wanted to make sure we tried to instill from the very beginning of the development effort was a strong emphasis on unit testing. We wanted to get the best training available that would be pragmatic and usable. I wrote an email to the pragmatic guys (Andy Hunt and Dave Thomas) and asked if they had unit testing training for development teams. Dave pointed me to Mike Clark.
At the time this name did not ring a bell and I was dubious. I did recognize some of the open source projects he has contributed so we contacted him. He already had a course in place called Test Driven Development with JUnit. We were thinking that we would want to significantly modify the training, but it turns out that it was just what we needed. We brought him on site and he significantly enhanced our teams ability to deliver high quality code. His content and presentation style was absolutely perfect for what we needed. It's the only 9 hours / day of training I have not snoozed through at least part of.
Since then I look for other internal groups that would benefit from his training, that have the budget and the time in their project timelines. I recommend this training to all Java developers who are not solid and consistent with unit testing.
If we were doing Ruby on Rails, we would have Mike here for months at a time as most of the stuff Mike does now is in the Ruby and Ruby on Rails comminities. However, he still teaches the TDD / JUnit class for those of us in large enterprises that see J2EE in our future for years to come.