A few years ago, I posted about a business student whose internship project was to increase daily revenue of a panhandler through adjusting the emotional pitch of the cardboard sign. In the same spirit of responsible citizenship, Daily Conversions blog decided to do a split test on another pandhandler's banner. Results? "This experiment improved this man's earnings by over 100% over several days."
An important finding: holding your cup up doesn't do anything for your conversions.