I've only made the lightest use of it, but I am officially declaring JUnit
and unit testing in general to be nifty. It helped me make sure I didn't turn in a buggy homework assignment. I figured I had made the last necessary tweak to the program, but when I reran the tests it still came up saying 9 had passed and 1 had failed. At which point I looked at the pile of "if elses" and realized I had only checked to see if one of the two variables was below the acceptable range, leaving it still free to slip through above the acceptable range.
Pretty good for something I can mostly only use with a cookbook approach. "Ah, so I just copy that and change the class names to mine... oh and thats how I check that this matches that..."
In other words, yes I'm enjoying my Java class.