Buttonizer is a simple utility that will throw a script onto a shelf for you. I got tired of constantly adding commands/scripts manually, then finding an icon and sticking it there, changing the Overlay label and changing the actualy popup tag.
So what this will allow you to do, is find the script, you can load anything but if it detects the extension as NOT being a .MEL file .. it will not let you use it. You can then use any icon type, preferably 32x32 bmp/xpm file ... There is even a "test button" so you can see how it will function before you throw it up there. It also will query all your current shelves and let you choose the shelf you want to throw it on...
Enjoy and stay in touch,