What's up?
"I'm outta here" (I am out of here)= im leaving now
"You gotta be kidding me."=You must be joking.
Hmmm. I hadn't thought of that before.
Let me see if I understand you correctly. . .
Are you busy?
Interesting point. I would add...
You might be right, but . . .
Anyway,
What were you saying?
etc etc etc
:]