Exradia has launched a range of replacement batteries for popular models of mobile phones which incorporate its special magic circuit to interfere with the bad RF coming from your handset, but iPhone users, with their non-replaceable battery, will just have to suffer.
According to the release Exradia are "...surprised Apple has chosen to ignore this potential health issue", though the company admits there's no evidence that mobile phones cause problems that's no reason not to make a buck preventing those very problems.
To be honest, there's no definitive study either way, in terms of radiation from cell phones or other devices. If in fact we ever discover this is a problem, we're all in big trouble. Until then, no sense not trying to make some cash, just in case.