You're dashing to a date, an appointment, a something-or-other. Rats, a chatty colleague spots you and drawls an untimely "Well, hello, let's chat for while" grin.
Usually poor souls ambushed like this furrow their brows; blurt out rapid excuses while prancing in place like a horse being kept from his feed bag; then gallop off. That wins you about as much respect as "Alice in Wonderland's" frenzied White Rabbit – and makes them feel like the Mock Turtle.
No, here's your strategy. As soon as you spot your colleague, come to a smiling and screeching halt. Then YOU give that leisurely "Let's chat" smile. And, yes, do chat — for about ten seconds!
Then, so you don't look like you're making a prison break, gracefully explain your rush and take your leave unhurriedly. However, when you're just a few feet away, pick up your pace to practically a sprint — to support your story. Now they feel valued, you retain their respect, and it doesn't take any longer than doing the insulting white rabbit break dance.