Here are a variety of scripts that utilize or can be deployed from buttons. A clever little button that gets annoyed the more you press it.
Typewriter effect writes a label on a button.
This script uses a button object and an onClick event handler to create a handy e-mail button. This script creates a scrolling text button with configurable text effects. This button changes color when you mouse over it. Display multiple versions of text on a clickable button. This script will open a window to full screen via a button or link.