Methamphetamine and Identity Theft Study Act of 2005 - Directs the Attorney General to conduct a study evaluating whether there is a connection between the commission of crimes involving methamphetamine and the commission of identity theft crimes. Requires such study to include a statistical analysis of any correlation and to evaluate: (1) imposing a sentencing enhancement if a person commits both; (2) establishing a password-protected electronic clearinghouse within the Department of Justice for federal, state, and local law enforcement agencies to share information on crimes involving both; and (3) whether individuals who use methamphetamine are more likely to commit certain kinds of identity theft crimes, such as through the use of mail, than are others who commit identity theft crimes.