Geekosphere
The area surrounding one's computer where trinkets, personal mementos, toys, and "monitor pets" are displayed. A place where computer geeks show their "colors."
Off the Grid
Euphemism for being off the Net. "Sorry I didn't email you last week; I was off the grid in Mexico." Also refers to someone who lives in a rural area without running water, electricity, or phone service.
PEBCAK
Tech support shorthand for "Problem Exists Between Chair And Keyboard." A way of indicating that there's nothing wrong with the computer - the user is clueless.
Yuppie Food Coupons
Crisp US$20 bills that spew from ATMs everywhere. Often used when trying to split the bill after a meal. "We all owe $8, but all anybody's got is yuppie food coupons."
Zen Mail
Email messages that arrive with no text in the message body.
Tip o' the mortarboard to Jim Leftwich, Steve Read, Darryl Lee, and Jon Lebkowsky.