Progressive Form

This example shows how a form can be created which progressively shows new options as the user makes choices. First a directorate is selected, then an organization. If the organization is not listed, the user can select other, and an input textbox will appear to allow a new entry.

This example can be used any time a site needs to guide the user through a complex series of choices.

Example modified from Remy Sharp's Blog

This example is the same principal, using the jQuery select plug-in

I have turned this concept into a plugin. You can download the plugin at Google Code and catch the demo there.