The piano in ensemble. The piano in real life.
***Ability to remember faces and names from the entire extent of one's professional network (ie. usually about 100-200 people)
I think this is where having a blog can really serve as a wonderful memory aid - i've used my own blog's search function several times to track down items that otherwise slip my mind. Since adding a picture gallery, i've been forced to track down names of folks in pictures that i would have otherwise completely forgotten. Keeping my pictures titled and named will serve me well into the future, i'm sure. My new podcast series is also mostly self-serving, helping me to get better acquainted with other musicians and trends in the musical ether. My brain is too small to keep the names of all the folks i need to remember on the front burner - that's why i use a PDA in conjuction with my blog!
That's brilliant. What's toughest is remembering people from years back, rather than months.
Add some facial recognition software to your sunglasses and you'll be all set (they use some pretty sophisticated programs for Vegas casinos - their cameras can instantly detect individuals to either send greeters for important clients, or security guards for miscreants...)