In the United States, it's legal to integrate money into artwork as long as you follow specific guidelines. (To research those guidelines or explore the rules for non-U.S. currency, go to www.rulesforuse.org and select a country.) But erring on the side of caution, Photoshop sometimes recognizes money and tries to stop you from using it. Fortunately for law-abiding citizens who are smart enough to follow rules, Deke knows a workaround.

http://digitalmedia.oreilly.com/2006/05/03/dekepod.html