"I'm in a meeting."

*Ring ring*

"Hi Joanne"

"Who's that?"

"Scott."

"I'm in a meeting."

"Ah OK, I'll leave you to it then and call back another time."

"What's this about?"

"You're in a meeting - it can wait."

"Well who are you!?"

"Like I said, you're busy so happy to call back."

"It's OK - I'm pretty much done here. So tell me, how can I help?"

Funny how so many people pick up mid-meeting...and then said meeting magically disappears when you agree to leave them to it.