It seems that pkg_* tools unpack stuff in /var/tmp If this is true, I guess we could deploy a speed hack unpacking in /usr/foobar-tmp*
Since most software is installed in /usr, this should cut I/O transfers a lot. Note: /usr and /usr/local could be two separate filesystems, so maybe we should use one these paths: /usr/local/tmp /usr/ports/tmp /usr/tmp
