A slight improvement on browsing would be to look at just the manifest file. You can see an HTMLified version of it here (using CGI-Application as an example): MANIFEST. You can see the source, if you know the version, as here: MANIFEST source. You could, of course, use WWW::Mechanize to go from one to the other.

If you run your own CPAN mirror, or use minicpan, you can write a simple script to check manifests for you, too.