latexchanges.py (Jan-Ake Larsson):
Here's a wrapper I wrote for latexdiff, intended as a drop-in
replacement for latex, when you have several numbered (or dated)
versions of a manuscript. My coauthors don't as a rule know what CVS or
SVN is, they simply use a number or date for the different versions.

latexchanges replaces the current DVI with one that includes a
latexdiff to the last version. The last version is selected as the
TEX file in the same directory with the same prefix (up to a number
or a dot), that has an mtime immediately preceding the given TEX
file.