Probably my location memory. I've been able to find my way back to places even when I wasn't playing close attention the first time around, and if I am paying close attention, I can find my way around nearly forever afterward. Drop me anywhere in the middle of Yokohama, and I could easily find my way back to my dorm room I was in two years ago.
Not a whole lot else remarkable about me, really. Even the tendency to accumulate random knowledge is just slightly above normal...but not when you hang out with geeks.