Michelle
A rice bag works nicely. (also take MOTRIN it's an anti-inflammatory). You can actually MAKE a rice bag yourself out of white rice and flannel. Put it in the microwave for however long you need (my size needs @ 3 minutes), the moist heat is good relief for a stiff neck. Also good for cold hands and feet in the winter.
I love my rice bag! I made mine out of terrycloth, put a zipper on one end for easy removal of the rice so I can throw it in the wash when it gets dirty.