Amends the Use Tax Act and the Retailers' Occupation Tax Act. Provides that the taxes also apply to leases of tangible personal property, other than computer software, property that is subject to the Rental Purchase Agreement Occupation and Use Tax Act, and certain automobiles. Amends the Counties Code, the Illinois Municipal Code, the Civic Center Code, the Flood Prevention District Act, the Local Mass Transit District Act, and the Regional Transportation Authority Act to make changes concerning the taxation of leased property. Effective immediately.