I like dozing on the grass. It's not like real sleep, where hours go past and you lose a big chunk of your day - it's more along the lines of thinking, letting your mind wander, maybe dreaming a bit. And stretching out my midsection, to stop it from cramping up completely.
I should take a notebook with me - I had about 5 original concept ideas that I can't remember any of now. It's those forming concepts that I push and poke until I have a fun game idea, and I'd like to have a better record of all the games I've designed.