In addition to my playing WWF and Hanging With Friends, I have found a new game: Draw Something.
It's basically dictionary with friends and random people. Kind of takes a bit to get used to drawing on the screen, but it is fun to try and guess others' drawings and to find new ways to draw the words you are given to draw.
I have decreased the amount of play time with each of my games so that I don't have to write a letter to my dear friend anymore. I am being productive with my time and only play when I have a free moment that is not needing time for other necessary activities.
But, just like learning to type faster, these are excellent time eaters that are entertaining at the same time.