I just bought an Ableton Push. I plan on cracking open a beer and learning to use it after work. I figure if I'm going to entertain myself I might as well be learning too. I find making music to be both engaging and relaxing.
I find that making music (especially on a computer) is very similar to writing software in that they require both hemispheres of your brain. I love the state of flow that you get into when you're deep in a project.