I'm talking about jogging your mind, jostling your muse, getting the creative juices flowing. How? Go for a jog. Or a walk, a bike ride, a run. Get out of the house/office, get some fresh air (avoid city streets; if you're deep in thought, you might as well wear a target for muggers, not to mention the hazards of crossing if you're not really paying attention to traffic).
Aside from the obvious health benefits of physical activity, it enhances creativity.
You don't have to go for a hard run or spend an hour at the gym. Moderate activity (a brisk walk) stimulates creative function in the brain immediately after you finish the activity AND for a good two hours after. (For real: check this out.)
Wrestling with an idea? Haven't seen your muse in a while? Go for a walk (jog, run, bike ride) when you'll have some time to write afterward. When I'm struggling, I sit down to write in my journal after a walk, and the problems, more often than not, resolve themselves.
And your back will thank you.
How do you overcome creative block?