Recently I created this little executable that will install Adobe Flash for Mozilla Firefox and Google Chrome for non administrators-- Need some testers.
Download it here: http://www.filedropper.com/flashfix01englishpaf
Please note that it will only work if you've installed the browsers in their default locations (using their original software installers).
So far it's been tested to work on Windows XP workstations that DO NOT have admin rights.
[I apologize for not following some of the guidelines for dev portable apps -- I was in a bit of a rush]