I met a guy in NYC 20+ years ago who told me his was 14 inches.  I didn't get to measure it but he was standing naked right in front of me and I believed him.  Hell of a nice guy too, we actually kept in touch by letter for a few years, he always looked on it as a bit of a curse but man it was great to look at (but frustrating to suck on!).

My buddy knows this guy, he's from Long Beach apparently.