Jeffrey L. Rubinger & William B. Sherman (both of Holland & Knight, Ft. Lauderdale, FL) have published Holding Intangibles Offshore May Produce Tangible Tax Benefits, also available on the Tax Analysts web site as Doc 2005-2977, 2005 TNT 30-16. Here is the Conclusion:

The holding and development of intangibles outside the United States can produce significant tax savings if structured correctly. Not only should the intangible property be held in a favorable treaty jurisdiction, but the development of the intangible should be part of an active trade or business conducted outside the United States to ensure that the royalties are not treated as subpart F income. In addition, by taking advantage of the check-the-box regulations, it may be possible to use a hybrid entity to hold the intangible and reduce the foreign tax imposed on the royalties as well.