Its a new feature aptly named "conductive touch". Comes in handy when your phone is on silent. Instead of vibrating, it just shocks the crap out of you. Its also fully configurable. Go to General-Settinngs and you'll see a myriad of options....
Text message = 5-15 volts
Call = 30-50v
Reminder = 15-30v
Alarm = deplete battery and set fire to surrounding area or electrocute owner. <- Bit of a wild card this one.
Conductive touch works in tandem with the iPhones new anti-drop feature "iNotFall". When activated, once you pick up the phone, it pumps out 220 volts, causing your hand to clinch the phone and not let go. Don't worry, they've upped the battery capacity to handle the load and you create a "safe word" for Siri during setup. Both features are popular with the S&M crowd and Moms love them because their kids aren't breaking their phones
BTW: Yous have to accept the terms of use before either feature is enabled.
This changes EVERYTHING!........
PS: Be sure to check out "iLive", one of the new components in Health Kit. Offers on the go defibrillation.