Limit iPhone radiation exposure + boost signal strength

Flipping through the iPhone manual, I happened upon this nugget of info.

“For optimal mobile device performance and to be sure that human exposure to RF energy does
not exceed the FCC guidelines, always follow these instructions and precautions: When on a
call using the built-in audio receiver in iPhone, hold iPhone with the 30-pin connector
pointed down toward your shoulder to increase separation from the antenna.”

Translation: Keep you hand off of the plastic antenna cover.

I wondered if anyone had measured changes in signal strength when “holding the iPhone properly” and sure enough Nate True posts “iPhone tip - want better EDGE speeds? Take your hand off the antenna”  He claims that he sees a 50% speed increase.  It seems a bit faster to me, but who knows.