Amends the Internal Revenue Code to establish a program of tax benefits for businesses and individuals affected by Hurricane Katrina by creating a Gulf Opportunity Zone (or GO Zone). Provides similar tax benefits for businesses and individuals affected by Hurricanes Rita and Wilma and establishes a Rita GO Zone and a Wilma GO Zone to provide tax relief to hurricane victims in those disaster areas. Authorizes the states of Alabama, Louisiana, and Mississippi to issue Gulf Opportunity Zone bonds as tax-exempt facility bonds or qualified mortgage bonds. Requires that 95 percent of the net proceeds of such bonds be used for the cost of qualified residential rental projects and the cost of acquisition, construction, reconstruction, and renovation of nonresidential real and public utility property in the GO Zone. Prohibits GO Zone bonds from financing certain prohibited projects in the GO Zone, including private golf courses, country clubs, massage parlors, hot tub facilities, suntan facilities, racetrack or other gambling facilities, and liquor stores. Exempts GO Zone bonds from volume caps and exempts interest on such bonds from the alternative minimum tax. Terminates the authority to issue GO Zone bonds after December 31, 2010. Allows the issuance of mortgage revenue bonds and qualified veterans' mortgage bonds in the GO Zone on a preferential basis and increases limits for home improvement loans financed by such bonds from $15,000 to $150,000. Exempts interest on such bonds from the alternative minimum tax. Allows an additional advance refunding of bond obligations of the states of Alabama, Louisiana, and Mississippi that were outstanding on August 28, 2005. Increases amounts and allocations of the low-income housing tax credit for 2006-2008 in the GO Zone. Allows a $3.5 million increase in the state housing credit ceilings of Texas and Florida in 2006. Designates the GO Zone as a difficult development area for purposes of enhancing the low-income housing tax credit for GO Zone residents in 2006-2008. Allows a 50% bonus depreciation allowance for GO Zone business property placed in service on or before December 31, 2007 (December 31, 2008, for nonresidential real and residential rental property). Exempts such increased depreciation allowance from the alternative minimum tax. Increases or allows additional expensing allowances for: (1) GO Zone depreciable business property; (2) demolition and cleanup costs in the GO Zone; and (3) environmental remediation costs, including GO Zone sites at which petroleum products have been released or disposed of. Increases the tax credit for expenditures to rehabilitate buildings and historic structures in the GO Zone made prior to January 1, 2009. Increases the expensing allowance for the reforestation expenditures of small timber producers (owning no more than 500 acres) in the GO Zone, the Rita GO Zone, or the Wilma GO Zone. Allows a five-year carryback period for certain timber losses in such zones. Sets forth special rules for the treatment of net operating losses for taxpayers in the GO Zone, including extending the carryback period from two to five years. Allows casualty loss treatment of losses incurred in the GO Zone. Allows a tax credit for investment in Gulf tax credit bonds issued by the states of Alabama, Louisiana, and Mississippi after December 31, 2005, and before January 1, 2007. Requires 95 percent of the proceeds of such bonds to pay costs of existing bond obligations in such states or to make loans to political subdivisions of such states to pay local bond costs. Increases the new markets tax credit for investments in community development entities serving recovery and redevelopment efforts in the GO Zone. Allows operators of low-income residential rental projects to rely on income representations of tenants displaced by Hurricane Katrina. Sets forth rules for the treatment of public utility property disaster losses in the GO Zone.