What is a general cure for a stiff and painful neck?

Go see a DO: Gentle stretching is always good but if the problem is chronic i would see an osteopathic physician that specializes in osteopathic manipulation.

Exercise/Stretching: Many times muscle spasm and tension can be the cause of neck pain. It could be caused by the way you sleep, if you recently changed pillows, if your job involves moving your neck around alot. Typically strengthening the neck muscles can be helpful and stretching those right muscles can be helpful as well. Other thing might be to change your pillow or sleeping position to help decrease stress.