Source: Hospital Humor

A doctor and an attorney were talking at a cocktail party. Their
conversation was constantly interrupted by people describing their
ailments and asking the doctor for free medical advice. After about hour
of this, the frustrated doctor asked the lawyer, "What do you do to
stop people from asking you for legal advice when you're out of the
office?"

"I give it to them," replied the attorney, "and then I
send them an invoice." The doctor was shocked, but agreed to give it a
try. The next day, still feeling a bit guilty, the doctor prepared the
bills. When he went to put them in his mailbox, he found a bill from the
attorney.