You can safely drop /var/tmp/portage to reclaim a lot of space. /usr/portage will typically contain the distribution files for those pieces that you've emerged; you can remove these but re-emerging/updating would download them again.
To 'clean' your /usr/portage directory you could try removing the whole thing then drop a snapshot in place. I keep my distribution files in an alternate location (my local ftp space for other gentoo boxes on the internal network to retrieve from), but "du -h /usr/portage" still reports that I'm using 1.5 Gig. To me this is a small price to pay, especially since disk space is so darn cheap to begin with. -- gentoo-user@gentoo.org mailing list
