Maybe I missed it, but if you supply the output of disklabel and df, it would be easier to give advice.
The machine isn't in front of me right now, but the partition setup was using the 'wizard' defaults. In other words: /, /tmp, /var, /usr, /usr/X11R6, /usr/local, /usr/src, /usr/obj, and /home, in that order. All the usr's (except x11) and home are set for a couple gigs each but only using a few hundred megs collectively. /var is a few hundred megs and close to full.
Nuking src and obj will free up a lot, but I think it would make more sense to collapse all the usr stuff into just /usr, move home into where var currently is, and move var into the new space.
