What do you do to calm down?

I was feeling quite agitated this morning. I've been aware for a while that I don't seem to have any mechanisms of making myself feel calm. I don't have any 'stims'. I've spent the last hour reading the latest posts on this forum, and doing an Aspie Quiz on one of the threads, and I've found I feel much better now, calm and back to normal. I suspect because my mind became focused on doing something intently (replying to topics in detail, then doing a 122-question quiz), so it had no opportunity to wander and be distracted by whatever it was that was causing me to feel agitated.

What methods do you use if you're feeling agitated or stressed out by something, to make yourself feel calmer?