I have just discovered a very nice tool. I was looking for a solution that would allow me to include software installed via MacPorts in my Applications menu. I was looking for more than a simple symbolic link to a bash script. Something nicer, with an icon and some interactivity. Then I have found a reference to Platypus on a forum.

Platypus allows you to pack any command-line postd software into an .app bundle with a nice icon, or a droplet on which you can “drop” a set of files for batch processing.

You can bundle many different programs as an App: your scripts - Perl, Php, Python, AppleScript- , command line tools included in OSX or installed via MacPorts,etc.

Platypus is quite simple to use and comes with nice and helpful documentation.
If you like it, you can support the project with a donation.