Your friends are old (and you by association!) when their conversations are comprised of the following:
"I just got an iPod."
"Welcome to the 21st Century."
"Who is this Fergie person who's all over the place?"
"Fergie? The Duchess of York, of course."
"Wow, she looks great. That whole Weight Watchers thing did wonders!"
If anyone is looking for me, I'll be getting a colonoscopy followed by an afternoon of cane-waving from my porch at anyone under the age of 65.