First check these accounts. Did you have a parent that passed away? Perhaps you sold a house and didn't claim all the escrow. Did you have an rich relative who may have opened a Swiss Bank account.

There are over 55 billion dollars in these accounts and you may have some free money sitting in one of them. First check the obvious and see if you may have a claim to an inheritance or some missing money.

This site is for money that was never claimed
http://www.missingmoney.com/

Refunds for Mortgage insurance: www.hud.gov/offices/hsg/comp/refunds/index.cfm

For dormant accounts or ones with no activity www.dormantaccounts.ch/

Public Debt's e-mail address for savings bond inquiries.
http://www.treasurydirect.gov/indiv/research/securities/res_securities_stoppedearninginterest.htm

Refunds on retirement accounts: search.pbgc.gov

This site contains unclaimed funds for insured deposits or for dividend checks issued which were undeliverable or never cashed: www2.fdic.gov/funds/index.asp