Here is a link to a new study about how nicotine builds up slowly in the brain. I found this quote very interesting "His laboratory, for example, is working on a mist inhaler to deliver nicotine without any combustion." Sounds like an ecig to me.
Nicotine builds up slowly in the brain - Addictions- msnbc.com
Nicotine builds up slowly in the brain - Addictions- msnbc.com