BASH: more powerful than you can possibly imagine. . .  

Is a user's home-dir mounted on every compute-node?

for i in \
  `cat /etc/hosts | grep comp | grep -v head | cut -d " " -f 2`; \
  do echo $i; "ls -l /home/mbgnfae2"; done

Play all Led Zeppelin songs:

ls -1 /mnt/usb/led_zep/* | \
  while read line; do xmms2 add "file://$line"; done

How busy is Man2?

export SUM="0" && for i in \
  `qstat -u "*" | grep -v qw | awk '{print $9}' | egrep "[0-9]+"`; \
   do export SUM="$SUM+$i"; done && \
   echo $SUM && echo $(($SUM))