Anyone here use "Apple Mail To Do"?

[guitarist]

This is a feature in Leopard that I don't see discussed much. I've taken a few stabs at it, but it hasn't made enough of an impression for me to remember to use it. I'm not even sure I know how it's supposed to work. Makes me wonder if it's a Leopard addition that never caught on. Or maybe I'm missing something.

Anyone here have any success with it? Find it useful?