The #! at the start of bash, ruby, python scripts is called the hashbang. Its use with the Amarok install —
One or two days after writing the article about amarok1 installation on Arch, a new version of amarok1 with ruby1.9 support was uploaded. As most of the ruby scripts for amarok1 still work only with ruby1.8, I decided to keep my old version. Today, while I was looking through a few bash scripts, I realized that using #! in the needed ruby scripts was a better option. So, now I use the AUR package and just change the hashbang lines in my scripts to point to ruby1.8 exec. If only I had realized this earlier 😛 😛
Anyways, more info about hashbang here.