BTW, Kotlikoff (mentioned in your linked pdf) now says the rate for 2007 is 23.8% inclusive, or 31.2% exclusive.
In case I haven't told you this before, this is NOT about rates in my view it is a about FREEDOM!
The income tax is the governments primary tool for social engineering (it comes directly out of the communist manifesto) and needs to be put onto the ash heap of history ASAP if we are to preserve anything of this great republic for our posterity.