government

http://www.cbp.gov/linkhandler/cgov/trade/legal/informed_compliance_pubs/icp013.ctt/icp013.pdf The Federal Government's official document on distinguishing bolts from screws.

Gil's LotD
http://www.nathannewman.org/nbs/whytax.shtml A government budget simulator game.
The links to play are on the right.