Not to be pedantic, but it's "WEP," short for "Wired Equivalent Privacy." This is the mysterious and sometimes dreaded encryption that is included in the 802.11b standard. Definitely enable it and use a good password. A lot of people poo-poo this, with the excuse that it can be broken (not by you or me, and not in real time, but yes, it can be broken) so it's useless. WRONG. War chalking is the process of identifying open wireless networks (through War Driving or even War Walking-wandering around with your wireless laptop and special software, just looking for open networks), and then marking them, as with chalk on a curb, or sometimes a map that's privately circulated among people who get their kicks out of using other people's networks. Yes, use it-it isn't really difficult.

Nebrie is right-if you enter hexidecimal characters (copied from your other computer's settings, for example)you have to use the "$" in front of them to tell the AirPort software how to use them-they'll be seen as plain text otherwise. However, if you're using an iBook or PowerBook and an AirPort Base Station, just as long as you enter the same text, they will interpret the inputs identically and they will talk.

Good luck.