This is the link to the PDF file of the Congressional Budgeting Office Analysis of Bush's SS plan, basically debunking Private Account as being too costly, and ultimately being a benefit reduction.
If we even hope to have a fighting chance in winning this battle, then its not enough to just say "but the CBO report says Bush is wrong", its also important to read the actual document and arm yourself with knowledge when engaging your freeptard sparring partners.
Its 57 pgs long, I printed off my laser on "ink saver mode" with side pdf slides to every page. If you can print it front and back then I recommend that you do that too.
I plan on reading and understanding it, I hope you will too.
http://www.cbo.gov/ftpdoc.cfm?index=6044&type=1