I'd never really thought about whether there was a scripting language with Google Docs spreadsheets (the same way that there's VB scripting with Excel). But really it makes sense for there to be Javascript there. (I have no idea if it's a new-ish feature, or has been there all along.)
This article from Blogger Xpertise not only got me thinking about the possibilities, but also has a useful script for making embeddable custom forms created in Docs a good deal more useful
