I've been trying to get Growl notifications to stick for Mail.app using GrowlMail, but the only one that seems to actually stay until I click on it is "Bubbles".
I tried "Bezel" and "Music Video" but they seem to ignore the checked sticky box.
Am I right in assuming that only certain notifications can be used as stickies? If so, why bother having the option in the first place on the ones that cant use it?