This is definetley *not* a bad idea, it would allow both BSDs to share
  distfile mirrors (and, in the future it would reduce a bit the need for
  disk space on mirror servers)

Not only that, but I use http_proxy and ftp_proxy to point my pkgsrc
builds, among other things, at a squid.  'make fetch' goes very fast
on subsequent machines.  Sharing bits with FreeBSD ports would be a
win.

It would be cool to cache distfiles themselves, rather than specific
URLs.  pkgsrc/pkgtools/dfdisk looks like it might be extensible to
support looking for distfiles on other nearby machines, or even gasp a
p2p network for sharing distfiles

-- 
        Greg Troxel <gdt@ir.bbn.com>