The "Flat Tax" vs the "Fair Tax"

Given the success of the flat tax in places like Hong Kong and Europe (BusinessWeek), I figure it's only a matter of time before it's actually more seriously considered in the US - particularly following its flirtations with disastrous fiscal policies. On the other hand, given the entrenched special interest groups in having separate deductions for pet projects, any form of tax simplifaction always has an uphill battle. Here's a pretty good primer on both the Flat Tax (imagine being able to do income taxes on the size of a post card) and the Fair Tax (taxing consumption versus income).