Thanks for the links Niall.
I'd been looking at the one from Stefan's blog but couldn't figure out how it was doing the popup list...also, it needs version 9 to work.
I'll take a look at John's it looks interesting (and compatible to version 7).
It's weird, I've been googling around the last couple of days and that link to John's blog never showed up. Guess I need to adapt my search terms...