If anyone wants an introduction to functional programming using Scala, I really recommend Martin Odersky's coursera course (https://class.coursera.org/progfun-2012-001/class). He restricts you to functional Scala; there isn't a mutated variable in the whole course. It isn't officially a course right now. You won't get a certificate for taking it, and I don't think the grader is turned on, but the other materials are still there.
That course does not allow registration right now.