I did what you advised, and noticed I missed the test data from Slick, added that and...
Guess I must be doing something right this time. Thanks!
At first I used lwjgl_util.jar and slick-util.jar. Maybe that's what I was doing wrong?
Edit: Emmmm, no... that wasn't it either. Apparently I had unknowingly set Eclipse to build a test application rather than my own. All is well now. I'm happily going through the tutorials making SlickBlocks to begin with.