Secure Rural Schools and Communities Funding Act of 2006 - Amends the Internal Revenue Code to: (1) establish in the Treasury the Rural Schools and Communities Trust Fund to make payments to eligible states and counties under the Secure Rural Schools and Community Self-Determination Act of 2000; and (2) require the withholding of three percent of any federal payment for goods and services and the transfer of an estimated amount of such withheld funds to the Trust Fund.