I had an application go nuts a week or two ago, and it filled up /tmp on one of my Solaris 10 hosts. Since /tmp is an in memory file system, you can only imagine the chaos this caused. :( To ensure that this never happens again, I modified the tmpfs entry in /etc/vfstab to limit tmpfs to 1GB in size:
$ grep ^swap /etc/vfstab
swap - /tmp tmpfs - yes size=1024m
That will teach that pesky application. :)