chmod mistake

["Masatran (Rajasekaran Deepak)" <masatran@research.iiit.ac.in>]

I accidently executed "chmod -R a+rX ." on my home directory. I want to undo
its effect.

1. Is there any way to undo its effect? (I do not have any recent backup,
and the administrators do not maintain a backup.)

2. "find" in my home directory gives 1,300 files. Is there any utility that
can be used to adjust their permissions quickly? (I will mostly be
recursively setting permissions on directories.)
-- 
Masatran (Rajasekaran Deepak) <http://research.iiit.ac.in/~masatran/>