Last night my iPhone's screen started becoming progressively less sensitive to input (multitouch and single). Got to the point where I could not even slide to unlock or type in my passcode. Tried all resets, restores, etc, no cigar. Everything else worked (volume, home button, vibrate switch, etc) -- would receive calls (just couldn't answer ). Anyway, made an appointment with a Genius and was in and out within 3 minutes with a replacement iPhone. I was very impressed with their responsiveness and willingness to not put me through the "standard" warranty process of taking a $29 hit on a loaner phone and having to send stuff through the mail. Very happy with how Apple took care of this. On another note, anyone have similar touchscreen issues (seen a few isolated threads about this, but no flat out failures)...any idea what the cause maybe? No drops, no water, nothing...just out of the blue stopped working.