Flash Hacking

Read this:

http://code.google.com/p/doctype/wiki/ArticleFlashSecurity

Then this:

http://www.ivizsecurity.com/blog/web-application-security/testing-flash-applications-pen-tester-guide/

Then this:

http://carnal0wnage.blogspot.com/2009/11/decompiling-flash-files-with-swfscan.html

Also, attend one of Kevin Johnson’s talk on the subject, not sure if his stuff is posted anywhere yet though.