The US $20 bill got a facelift Tuesday, complete with new colors, a new
number arrangement and a new background, in the government's latest
effort to thwart counterfeiters.

Some sites to help in this effort:

Fed101: Federal Reserve System Economic Education
http://www.kc.frb.org/fed101/  

$20 bill gets a facelift 
http://money.cnn.com/2003/05/13/news/economy/twenty/index.htm 

Historical American Currency Exhibit
http://www.frbsf.org/currency/index.html 

Money Museum
http://www.rich.frb.org/econed/museum/  

Federal Reserve Bank of Minneapolis: Money Curriculum Unit
http://minneapolisfed.org/econed/curric/money.cfm