Who uses it: Physicists and electricians
What it means: An enclosed hollow space designed to block electromagnetic fields, where the electrical current goes around the outside of the space rather than through it.
How you can use it: When you can't get cell phone reception.
Thanks to Claire Bea for bringing this term to my attention; she mentioned last night that Metro trains are natural Faraday cages, which is why cell phones don't work there. (And thank goodness for that.) Automobiles are also crude Faraday cages, which is why they're relatively safe places to be in a thunderstorm.
Dizzy and I are back in Washington, and I've lost track of what day it is. Today I'll catch up on some work, call some friends, and reorient myself before heading to Maine tomorrow.