I use a CPAN module called Filter::Handle that might do what you're looking for.

use Filter::Handle qw/subs/;

# point STDERR to /dev/null, otherwise web server throws a 500 error i
+f you print to STDERR, even with zero-ing out the output via ()

open(STDERR, ">/dev/null");
Filter \*STDERR, sub {
    fatal @_; #fatal is an internal sub to e-mail the devs
    ()
};
[download]

The only problem with this approach is that it doesn't seem to Filter the STDERR output from other CPAN modules (say, HTML::Template) which is what I was trying to accomplish in the first place. Maybe someone more versed in Filter::Handle can explain that for me.