I think, without restriction, that Fink is worth the trouble even for the comparatively small task of installing DBI. :)

Again, yes, but with the caveat that this also means getting Fink installed, then using it to compile and install a new version of Perl, and never using the default Perl.

While I understand that you might not view this as a restriction, people who are looking for a minimal level of modification might still prefer to use the CPAN software they already have installed, and just maintain one version of Perl. (As noted elsewhere, upgrading to Mac OS X 10.3 gives you Perl 5.8.1.)