This is nice in FF on the Mac but doesn't seem to work in Chrome on the Mac (not that developers <i>need</i> to support a beta browser quite yet).
After building and using some complex web apps, it would be nice if there were search boxes like this that quick-linked to functions in the application. For example, if I am new to a project management application, and need to find something obscure like, "login settings", it would be nice if I could type "login" and see a list of things that matched that function.