Ah, I see.
!#/bin/sh is the "shebang." Tells the shell what shell (or language, even) to run a script in; potentially, it allows you to type "./scriptname" instead of "/bin/sh ./scriptname" to execute a script.
For example, if you run bash as your shell, and there was an executable script with no shebang, it would use bash instead of sh, which might cause problems...of course, bash and sh are supposed to be pretty compatible, but a lot of guys use tcsh, ksh, zsh, etc., and that would be a lot riskier.
Also, since the Bourne Shell is a standard, you'll find it on every 'Nix, which is a big reason scripts are written in sh.
You'll also see shebangs for PERL and PHP, and maybe other languages as well.
