I charge my iPhone 4 right next to where I build my circuits, so I'm always simultaneously looking up datasheets, texting and so on. What's interesting is whenever I touch the rail/antenna of the iPhone, and any grounded part of the circuit, I feel a searing heat and surge of current focussed on the spot where contact with the circuit's ground is made.
Why is this? I measured for current and voltage just with a multimeter and found nothing. Is it the positive signal of the antenna being shorted to ground?