fwiw, it's *extremely* convenient to be able to rm -rf /usr/pkg and
  /var/db/pkg and start from scratch, on any pkgsrc system, anywhere.

I agree, and I do this, but usually 'pkg_delete -r \*', and then
delete crud from /usr/pkg, saving etc.

Someone else mentioned NFS.  I've always found it odd that /var/db/pkg
isn't in e.g. /usr/pkg/var/db/pkg.  With that, one could
reasonably NFS mount a /usr/pkg for some arch, and even modify it from
any of several machines.  And, it would make using pkgsrc on a FreeBSD
system easier, since ports and pkgsrc could coexist, modulo which
prefix was used to select pkgtools versions.


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