P.L. 104-191 contains changes in the taxation of U.S. citizens who renounce or otherwise lose U.S. citizenship. In general, any person who lost U.S. citizenship within 10 years immediately preceding the close of the taxable year, whose principle purpose in losing citizenship was to avoid taxation, will be subject to continued taxation.
Renounce your citizenship for something other than to avoid taxation. Like, you're suddenly in love with socialized medicine. Or to "protest the war" or "America's imperialism". Just don't mention taxes in your "exit interview" and there you go.
http://travel.state.gov/law/citizenship/citizenship_778.html