One of my relatives, who shall remain nameless, had horrendous knee pain and could barely walk. His mom recommended that he go see her doctor. He went in and the doc asked him to lay down and the next thing he knew he felt some "nail-like" pains in his knee as the doc shoved in acupuncture needles like a martial artist.
Of course, his mom had neglected to tell him the doc was an acupuncturist, because she knew he wouldn't go otherwise. His comment to all of us: "I'm glad I wasn't having pain in my testicles." Most importantly, the pain in his knee mysteriously disappeared.
This is the mystery of acupuncture: until recently no one could quite figure out how it worked. Scientists, though, in the last decade have made numerous discoveries about acupuncture and its effects on the body. One of the most powerful seems to be acupuncture's effects on inflammation. (Acupuncture also seems to affect certain cerebral and circulatory centers as well.)
One sign of this is that acupuncture has shown some remarkable study results when it comes to inflammation-related diseases. For example, one study of patients on steroid inhalers for asthma achieved a 96% success rate.  Some critics like to point out that there is likely a very powerful placebo effect with acupuncture. However, can you really argue that a 96% success is because of placebo? A better word for that is "miraculous".
Acupuncture also has a long history of treating seasonal allergies (rhinitis). Several studies have born this out, including one where three fourths of patients were permanently cured from treatment and another fifth improved significantly.  Again, this success rate is too high to be explained by a placebo effect.
Other examples abound: acupuncture has helped patients with other inflammatory conditions such as arthritis and Crohn's, etc. And, if you stop and think about it, these are amazing benefits considering, in general, the effect cannot be local. For example, in the case of asthma, the needles are not not anywhere in the vicinity of lung tissue. The same can be said for treatment of intestinal disorders such as Crohn's. Clearly, something much more sytemic is going on.
The answer may like in the fact that acupuncture has been found to reduce some of the major inflammatory markers, such IL-10 and TNF-alpha. In addition, certain neuropeptides are affected in a positive manner as well. So, while acupuncture may seem counterintuitve, i.e. why would insertion of hair like needles into the skin produce such significant and profound effects? - its healing powers actually begin to make some sense. So the bottom line is that you may want to consider acupuncture as a possible treatment option for conditions that are tied to inflammation and pain.
NOTE: One key in the above-mentioned asthma study were many treatments over several weeks. There have been some studies of acupuncture with less-than-stellar results and experts speculate that it may be that treatment was simply too infrequent.
1) J Tradit Chin Med, 1998 Mar, 18(1):27-30, "Clinical observation on 25 cases of hormone dependent bronchial asthma treated by acupuncture"
2) Zhong Xi Yi Jie He Za Zhi, 1991 Dec, 11(12):721-3, "Desensitive treatment with positive allergens in acupoints of the head for allergic rhinitis and its mechanism"