Directory of Institutes, Organizations, and Clubs on Taxes and Taxation from Free-Market. The Tax Foundation is committed to a well-informed citizenry and simplicity and stability in tax policy. It is against retroactivity in tax laws, and supports neutrality in tax policies which do not hamper international trade. A new org that primarily focuses on economic policy issues, especially taxes. They also cover entitlements, monetary policy, and deregulation, and seek to bring the insights of Austrian economics to a wider policy audience.
Site looks pretty and is easily navigable.
Find extensive sections on budget reform, electricity deregulation, health care reform, the environment and trade policy. A non-profit association working for the common sense in taxation of personal savings and investments. This organization's main lobbying effort is to retain and encourage jurisdictional tax competition. They are actively opposing efforts by countries around the world to penalize low-tax countries which respect banking privacy. An independent tax watchdog group.