Yep - - or do as I did (because I didn't have room on the root (/) filesystem): Unzip it somewhere else, and just make a symlink to it in /
dd if=/dev/zero of=/media/hdd/Scratchbox.fs bs=1024 count=3000000 mkfs.ext3 /media/hdd/Scratchbox.fs
mkdir /scratchbox mount -o loop -t ext3 /media/hdd/Scratchbox.fs /scratchbox