Inappropriate calls across the office....
At one time we had an internal sales team where only 1 spoke only English. The others were French, Russian and Spanish.
We had a customer who's since become a great friend. He liked to call the new Russian Internal sales lady to contact his sales account manager and announce himself as Ivor Biggin or Chris Peacock. Caused great hoots from the native English speakers when she announced him across the office and accelerated her English language education. PP :) Win, win.