Incidently, you can change that version of Perl on FreeBSD by doing

# cd /usr/ports/lang/perl5.8.0/
# make
# make test
# make install
# use.perl ports
[download]

That last command will set symlinks and whatnot, so that the new version is used by the system, with whatever ports are being compiled etc, and the source won't get overwritten on the next make world