I found this article on cNet about some brief plans of upcoming intel chips, sounds promising for low powered processors running as low as 0.5 watts =)
By the end of the decade, Otellini said, Intel would have another new architecture running x86 code as low as 0.5 watt--that is, about one-tenth the demand of the lowest-power version currently available. This could either be used for portable systems running at very low power, or standard systems running at 10 times the performance per watt of current designs, he suggested.
