Neck pain? Take two tennis balls and put them in a sock. Lie down on a firm surface and put the balls behind your neck, just beneath the shelf of your skull. Close your eyes and breathe deeply, then gradually reposition the balls further down your neck.
Tense muscles? Lie on the floor or back up against a wall and position the ball where you find intense soreness. The ball will add pressure to painful trigger points, similar to the way acupressure or acupuncture works.
(Source: The Fibromyalgia Handbook: A 7-Step Program To Halt and Even Reverse Fibromyalgia. By Harris H. McIlwain, M.D., and Debra Fulghum Bruce, M.S. Owl Books/Henry Holt.)