Basically, it's an expression used to symbolize
jealousy across the neighborhood and the need to
keep up with each other. It's usually just
technology, but the subject can be changed to lawnmowers, cars, etc.
Sometime in 2001...
Joseph: Dad! May I have the PS2?
Dad: No, you still have your
Nintendo 64, right?
Joseph: It can play
DVD's.
Dad: Okay, be prepared, I'll drive you to the
Best Buy.
Dad, this time on his mind: I'll have to keep up with the Joneses!