File::chmod might not have been my very first, but it was the first one I felt confident enough to package and submit to CPAN. It's even mentioned in "Learning Perl" (at least, in the 3rd edition), and Randal and Tom (Phoenix) mention it in all their tutorials. :)
in reply to I wrote my first Perl Module
I also wrote Tie::Dirhandle, which was just kinda weak.