Both today and yesterday I had about half an hour to do something and both times so far, I've picked writing. That means I'm up to 1388 words in my little journal and I'm having lots of fun writing it. :) It also means I haven't progressed as much as I'd like to with studying. I think I know what other things to blame for that. I'm looking at you, Miss Procrastinator. (Who me?)
I don't regret my choice. Half an hour of writing actually yields something, while half an hour of studying is just reminding yourself where you left off.