I don't find new things like this often anymore (been using moo for a fair amount of time), but this is kind of cool to know.
You may at some point or another want to have an accordion that has all it's panels closed when the page loads. I tried this on a hunch and whatdaya know it works! Drum roll: Set the option 'display' to -1. I know, simple, but oh so sweet. - At ease gentlemen (I will be accepting compliments all evening...)
