Vaporization in general terms was used since the biblical days. In the story of moses when he stated that when he wanted to talk to god he would put on holy oil and go int the tent and light "incense" which was most likely a term for inhaling hash fumes as far as it being cannabis there are debated on that.
As far as modern day types of vaporization the earliest known come from the rastas of jamaica who been doing it since the 1950's. They used a bamboo bong and coconut charcoal to vaporize the herb like we do now.
I think I read Sam Skunkman saying he or someone else went there in the '70's and saw it being done and returned back to the states trying improve on it but I could be wrong because this was a while ago I read this.
Here's articles on moses in the tent:
http://www.cannabisculture.com/articles/1090.html
"The shamanistic Ashera priestesses of pre-reformation Jerusalem mixed cannabis resins with those from myrrh, balsam, frankincense, and perfumes, and then anointed their skins with the mixture as well as burned it.'"
Here's about the original jamaican vaporizer:
http://www.cannabisculture.com/v2/articles/4281.html
"The steam pipe is an organic vaporizer made from bamboo, using a small saw, a granite rock surface for a sander, and candle wax to seal the connections and to ensure air-tightness."