A thread was started recently on the Boater's Forum on the topic of tendonitis and treatment. Many of the posters seem to support the use of acupuncture, homeopathy, and other alternative medicine to treat medical issues. I believe most of alternative medicine is useless for treating anything physiological, but would rather not flood that thread with the debate!
Homeopathy operates on two basic principles: like cures like, and dilution increases curative strength. In fact, in many homeopathic remedies, the original substance is diluted to the point that it no longer contains a single molecule of the original substance. It is magic water. It has also shown no success in double-blinded clinical trials. For a skeptical analysis of homeopathy, I highly recommend James Randi's presentation on the topic:
Acupuncture claims that everyone has an undetectable, unmeasurable "qi", that can be manipulated by inserting needles into meridian points. Unfortunately, we have only figured out how to perform double-blinded trials with acupuncture in the past decade, so solid clinical trials are hard to find.
The only area in which acupuncture appears to beat acupuncture is in pain management, but randomly sticking needles to shallow depths in people shows the same effect. If the needles are inserted in random locations, instead of at meridian points, is it really still acupuncture?
One aspect that has been adopted by alternative medicine that I do accept is that people tend to get better on their own. People have a medical issue, try homeopathy (or conventional medicine, or acupuncture) and get better within a week. Odds are, they were going to get better anyway. That's why we need to conduct controlled, double-blinded studies instead of relying on anecdotal evidence in evaluating treatments.