Question
I've recently developed what I believe to be tendonitis in my right wrist.  The pain is completely on the top of the wrist, not the underside.  The pain is exacerbated by rotation movements and flex movements, both up and down.  Unfortunately, my job requires lots of computer work and manual writing (which is the worst).  Do I need to rest my wrist, or can I get away with icing or heating it alone?

Answer
From your description, it sounds as if you have a repetitive strain injury to the wrist (RSI).  In order to fully let it heal, you would have to rest it completely.  Icing can help, as well as an anti inflammatory.  If you have no relief within a few days, I would suggest trying a chiropractor.  They would be best suited to determine if it is a simple strain, a misalignment causing the pain, or a more serious problem that would need a referral.