root@grml ~ # mount /mnt (note: zsh removes the slash from /mnt/ because it's
being smart here)
mount: can't find /mnt in /etc/fstab or /etc/mtab
1 root@grml ~ # mount /mnt/ (note: i typed in the / anyway because i am smarter)
root@grml ~ # mount |grep hda
/dev/hda7 on /mnt type ext3 (rw)

umount works in both cases with /mnt and /mnt/