Well, Wikipedia has a decent article here: http://en.wikipedia.org/wiki/Electronic_cigarette
Pay special attention to the Health Issues section. In summary: we don't know yet what long-term effects are; they still contain nicotine, but no tar; and a toxin has been discovered in at least two brands (Google reveals this isn't a wikipedia-only statement) that may be from unintended side effects of manufacture, but is still potentially deadly (diethylene glycol).
The FDA has not yet approved them fully, and not all manufacturers pass what standards there are in their rush to get products to market.
In shorter summary: if health is a concern, chew on toothpicks instead.
Edit, meant to include this originally but hit post by mistake: Google also reveals that there is considerable shouting on both sides of the fence on this one. So, y'know. Do your research and decide based on that. If you use a nicotine-containing flavorant, the only thing that is 'better' than regular smoking is the lack of, well, smoke (and associated nastiness).
--sofaspud
--"Listening to your kid is the audio equivalent of a Salvador Dali painting, Spud." --OpMegs
Pay special attention to the Health Issues section. In summary: we don't know yet what long-term effects are; they still contain nicotine, but no tar; and a toxin has been discovered in at least two brands (Google reveals this isn't a wikipedia-only statement) that may be from unintended side effects of manufacture, but is still potentially deadly (diethylene glycol).
The FDA has not yet approved them fully, and not all manufacturers pass what standards there are in their rush to get products to market.
In shorter summary: if health is a concern, chew on toothpicks instead.
Edit, meant to include this originally but hit post by mistake: Google also reveals that there is considerable shouting on both sides of the fence on this one. So, y'know. Do your research and decide based on that. If you use a nicotine-containing flavorant, the only thing that is 'better' than regular smoking is the lack of, well, smoke (and associated nastiness).
--sofaspud
--"Listening to your kid is the audio equivalent of a Salvador Dali painting, Spud." --OpMegs