I also suggest doing the neck stretches in the shower, under hot water, with the water directly on the neck. Remember to breathe and be patient, and do not overexert yourself here, or it'll exacerbate the whole thing.
1. Tuck chin
2. Love down
3. Right ear toward right shoulder. Keep that chin tucked!
4a. Rotate head down (to look at your shoulder).
5. You can increase the stretch by using your right hand to apply very gentle pressure to your head, or reach your left arm toward the floor.
6. Repeat on the other side.
Repeat all of the above except:
4b. Rotate head up to look at the ceiling. Again, remember to keep your chin tucked.
If you get a stiff neck frequently, do a few sets of chin tucks during the day. You can do this by lying down on your back and tucking your chin-your pillow will provide resistance.