Menu psychology - no $, more $

Consumerist:

"Have you ever noticed that the menus in nice restaurants leave the currency signs off prices, or spell them out in words rather than Arabic numerals? The intended effect is pretty much what you would assume - to remove the association between prices on the menu and actual money. Now, there's actual academic research showing that half of this theory is true."

The research compared menus priced with "$20", "20" and "twenty," and surprisingly, it was in establishments where the menus priced with "20" that people would generally spend more.