A man walks into a bank and says he wants to borrow
$200 for six months. The loan officer asks him what
kind of collateral he has. The man says 'I've got a
Rolls Royce -- keep it until the loan is paid off
-- here are the keys.' 

Six months later the man comes into the bank, pays
back the $200 loan, plus $10 interest, and regains
possession of the Rolls Royce. 

The loan officer asks him, 'Sir, if I may ask, why
would a man who drives a Rolls Royce need to borrow
two hundred dollars?' 

The man answers, 'I had to go to Europe for six months,
and where else could I store a Rolls Royce for that
long for ten dollars?'