Meaning/Usage: To stay connected

Explanation: When you can touch someone, you are literally close to that person. "Stay in touch" is indicating that the person wants to keep communicating so they will be "close" as friends.

"Call me more often man. We got to stay in touch."
"I hope you stay in touch with me. I'll give you my contact information."
"Let's stay in touch. I'll email you whenever I can."
"Are you staying in touch with her, or are you guys not talking any more?"

A: "Since you are moving to England, I'm really going to miss you."
B: "Yeah. I'm going to miss you a lot too."
A: "You promise that you'll stay in touch?"
B: "Of course. We'll always keep in touch."

Other Common Sentences

"Keep in touch. I'll want to know how you're doing."
"Julie told me that she would keep in touch with me."