Or, if you are too cheap to buy the book, and too lazy or dumb, to read it, you could (but I'llo bet you won't( go to these sites -- it won't cost you a dime:
http://denisbider.blogspot.com/2008/01/taxation-in-pictures-why-fairtax-makes.html
http://denisbider.blogspot.com/2008/01/taxation-in-pictures-why-fairtax-makes.html
http://www.fairtax.org/site/PageServer
http://www.fairtax.org/site/News2?news_iv_ctrl=1541&page=NewsArticle&id=8248
http://www.fairtax.org/site/PageServer?pagename=about_ask_question
http://thomas.loc.gov/cgi-bin/query/z?c109:H.R.25:
http://www.fairtax.org/site/PageServer http://64.233.169.104/search?q=cache:gogrXXoQcwEJ:www.pafairtax.org/resrcs/FlatTaxFairTaxComparison.pdf+fair+tax+fica+tax&hl=en&ct=clnk&cd=1&gl=us
http://www.fairtax.org/PDF/Open_Letter.pdf
http://worldnetdaily.com/news/article.asp?ARTICLE_ID=59747
It already is lacking in an adequate transition plan though.
Note that taxation systems work better when they are stable so people can do some long term planning. The uncertainty caused even by discussion of the FT will cause some negative economic outcomes too. Who is measuring/estimating that?