A cannabinoid patch might be possible many years from now:

Albany College of Pharmacy researcher Audra Stinchcomb was awarded a $361,000 three-year grant on 21 January by the American Cancer Society to study whether cannabinoids can be absorbed effectively through the skin.

The research could led to the development of a cannabinoid patch for therapeutic use. It could ease the pain, nausea and vomiting that chemotherapy patients can suffer, said Gail Tyner-Taylor of the American Cancer Society of New York and New Jersey.

[...]

"It could take a decade before a marijuana patch would be available," said Stinchcomb. "If the initial tests prove successful, animal tests and later human tests would have to be completed."

So that's that then, those of you who are in pain and vomiting. Meantime what are people to do? I'm not a doctor, but I was thinking that it might just be possible to introduce the substance by smoking it, as one would do with one's tobacco-pipe. Apparently not: "'Smoking can provide a high immediate dose and make some patients high,' said Stinchcomb." Ah, I see. No good, then.