Linux/OSS : cpan2rpm
cpan2rpm is a useful Perl script to allow you to install Perl modules from CPAN as RPMs. I take no credit whatsoever for this; it was written by Andy Jeffries but is distributable under the terms of the GNU GPL and is provided here for convenience.
It has absolutely no documentation (at present) and won't work for building as non-root by default. But basically, just modify the build tree paths to suit your needs, and do 'cpan2rpm Whatever::Module'.