I was wondering if there was anyway to set a timestamp field at the table level to update to "localtimestamp" whenever the record is updated.
Create a BEFORE UPDATE trigger that calls a procedure that sets your database column with the datetime.
There's this cool web site with code samples of how to do just this. It's called, I think, PHPBuilder. Here's the slab of code you want:
http://www.phpbuilder.com/snippet/detail.php?type=snippet&id=994
