Homeland Security Open Source Intelligence Enhancement Act of 2006 - Amends the Homeland Security Act of 2002 to direct the Secretary of Homeland Security to ensure that: (1) the Under Secretary for Intelligence and Analysis and the Assistant Secretary for Infrastructure Protection make full and efficient use of open-source intelligence (intelligence that is produced from publicly available information) by acquiring, gathering, processing, and analyzing open-source information to produce open-source intelligence products; and (2) the Department of Homeland Security (DHS) makes full and efficient use of such information to analyze U.S. critical infrastructure nodes from the perspective of terrorists using publicly available information. Directs the Secretary to share such analysis with appropriate federal, state, local, tribal, and private-sector officials.