I am terrible at doin' nothin', hangin' out, not seeking any self-improvement for an hour or two. Unless you count bouncing distractedly between Facebook and Twitter and email, ugh; I'm trying to cut back on that. It's not real relaxation, not if you're doing too much of it.
There are lots of activities I can do in alternation with my day job that are somewhat relaxing and shift me into a different place, but I need some true downtime as well, not just sneaky self-improvement.
PG-rated activities that do function as relaxation for me and are not sneaky self-improvement (For the most part):
• Salsa dancing (*)
• Reading science fiction
• Truly silly programming projects like the snowcam
• Playing Starcraft 2.
I still remember discovering the original Starcraft: I was visiting my sister and brother-in-law. Jason had a dedicated office-slash-gaming-room. He didn't have a PC, he had a rig, you know what I'm saying? It was a good cave in which to discover a game.
Speaking of caves, though, I love how you can fall into Starcraft and then come out again. Each match is self-limiting in duration. Nobody's trying to force you to "farm" all fricking day to get anywhere in the game.
Because it's a GAME. It's not a REPLACEMENT FOR YOUR LIFE. I like that.
After a concerted attempt to get good at playing the Terrans, I have rediscovered the joy of playing the Protoss... the one species in all of known space that can set up a decent static defense and build a slow, inexorable, overwhelming offense.
All of those things are good if you have never had the fastest reflexes in the world.
Plus, they have voidrays, which are terribly satisfying and strike more terror in one's opponents than their actual stats deserve.
And a decent build seems to come naturally to me, while I find the Terrans much fussier to play. I'm still not, y'know, GOOD. But I'm hardly ever that guy all the thirteen-year-olds are making fun of at the end of the game anymore. So... I win?
(*) OK, salsa can be sneaky self-improvement, especially in the early days of the learning curve. But at my level of experience going out to the club and spinning the ladies for a couple hours is strictly recreation.