I have never gotten in to urine therapy. I feel that the body is getting rid of urine for a reason. For instance it is getting rid of excess ammonia compounds, excess salts, excess glucose, etc. Ingesting what the body was trying to get rid of in the first place makes no sense to me. My biggest concern has always been the ammonia, which is very toxic to the body.
Externally it does have some applications though such as for the treatment of jellyfish stings. The ammonia neutralizes the jellyfish toxin. Urine is also said to be effective for fungal infections such as athlete's foot.