jboyd: What Tom said (RICE)!
One other thing to consider. There actually aren't any muscles on either side of your knee cap; ligaments and tendon's, sure, but the muscles are both above and below. There are several bursa in your knee (fluid filled sacks that provide a whole host of functions in a joint), and the area you describe as being swollen includes several of them. That being said, I'm not real good on the disease physiology of pneumonia, but here's what I would do if I was in your shoes. Start with the RICE thing that Tom talked about. On top of that, I would start taking one of the drugs in the NSAID group (Aspirin, Aleve, Motrin, Ibuprophrin, etc., not Tylenol, its in a different class and doesn't do anything for swelling). I would expect to see significant progress in about 2-3 days with the above.
Keep us posted.
D