2. There is no such chip with present technology. Smallest package is, reportedly, about the size of a pack of cigarettes. There are GPS transmitters that fit inside a cellphone (I have one) but not implantable - yet. A transponder (two-way) would be even bigger.
Thanks! I have had a discussion with several people about this same thing and it just surprised us all that the technology isn't there for this. But, I know our guys are doing everything they can!!