Meaning of "the seventies are calling"

I heard the sentence in a TV show (Fringe 4x16).

The guy's phone was ringing and his friend said:

"You should get that. I think the seventies are calling."

and they both chuckled as if at a joke. So I thought it must be slang.

I got no results from Google and was curious to know the meaning.

The person telling the joke is implying the person he is talking to is stuck in the past. "The Seventies" refers to the 1970's. The joke is often completed "I think the seventies are calling. They want their X back", where X is something associated with that decade.

I assume the guy whose phone was ringing was making an outdated pop culture reference or dressing in 1970's fashion.

Other decades are also referenced in the same way. Here's an example headline from Salon.com