Using the problems at http://projecteuler.net as exercises to learn Scala.
I am reading through "Programming in Scala: A Comprehensive Step-by-Step Guide" http://www.amazon.com/gp/product/B004Z1FTXS/
Right now I am focused on just solving the problems using Scala. As my understanding of Scala and functional programming improves I would like to spend some time going through past solutions and reimplementing them from a more functional oriented standpoint.