The FDA has just approved something called the HairMax Laser-Comb for men with male pattern baldness. It's a hand-held device you can use at home to stimulate hair growth.
The device does not use medication, rather it uses "laser energy" on the scalp to encourage growth. Studies show 93 percent of users saw an increase in the number of thick hairs on their head over a six month period. At least that's what the manufacturer says and the FDA agrees that it may be helpful.
At least 35 to 40 million men in the U.S. have male pattern baldness. Women suffer too, but right now, the laser-comb is only approved for men.