A smile

A Smile Costs Nothing, but gives much.
It enriches those who receive without making poorer those who give.
It takes but a moment but the memory of it sometimes lasts forever. 
None is so rich and mighty that he can get along without it, 
and none is so poor that he cannot be made rich by it.
A Smile creates happiness in the home, fosters goodwill in business, 
and is the countersign of friendship. 
A smile brings rest to the weary, 
cheer to the discouraged, sunshine to the sad,
and it is nature's best antidote for trouble.
Yet it cannot be bought, begged, borrowed or stolen,
for it is something that is of no value to anyone
until it is given away.
Some people are too tired to give you a smile,
Give them one of yours, as none needs a smile so much
as he who has no more to give.