If you missed it, be sure to review Medical Uses of Marijuana - Part 1 for an introduction and overview of this area.
Many people report using marijuana recently, usually via smoking, for pain relief.
In fact, marijuana was commonly used for this purpose up until the 1800's, when strong narcotic drugs, such as morphine, began to be more commonly used. However, animal studies tend to show analgesic effects, while human studies show more conflicting results. Evaluation of cannabinoids in the management of neuropathic pain, including HIV-associated neuropathy, should be undertaken. A few animal studies support this idea. So, it looks like one of the most promising areas for the eventual legal use of marijuana in the United States might be in controlling neuropathic pain, which is poorly controlled by existing drugs.