Quackery I'm in the middle of reading a fantastic book at the moment called "Trick or Treatment: Alternative Medicine on Trial" by Simon Singh and Edzard Ernst. They subject alternative medicine to the same scrutiny as - say - a new 'conventional' drug would get.
Conclusions so far: -
Acupuncture - a load of bollocks
Homeopathy - a load of bollocks
Chiropractic - a load of bollocks for anything other than back pain and even then, conventional treatments are as effective (or ineffective, back pain being difficult to treat), cheaper and safer.
Herbal medicine - proceed with caution with regard to side effects, but good evidence for some herbal remedies.