It's a new year, so it's time to reduce the size of CPAN.
A long time ago, I was really interested in measuring the growth of CPAN, and comparing that to the size of MINICPAN, which I called the Schwartz Factor.
I'm interested again because CPAN just filled up an old laptop disk and my FreeBSD machine got really concerned about where it would put files. CPAN is over 3 gigs. Yowsers! We can get under 3 if people can delete about 150 Mb of old versions.
Some of that size, however, is cruft and old versions of modules. Delete those older files! You'll still find them on BackPAN, so you don't need to keep them in CPAN.