Yahoo answers has some good tips on hair loss. I found this one today:

Question from Yahoo Answers:

What Causes Hair Loss And How It Can Be Treated Naturally?

Here was the best answer:

Hair loss can be caused by a number of things from genes (heredity causes) to use of chemicals that damage hair and treatments i.e. Chemotherapy. There are a range of different natural treatments available, you can also check out FDA approved products such as Regaine and Propecia.