Does Growl keep a history? Does Growl, either natively or with an extension, keep a history, possibly accessible through a graphic interface?

(something like Jumpcut, I mean)

I'm talking about OSX 10.6 (hence Growl 1.2.2), I dunno if the Lion version is different.
Growl 1.3 (available on the Mac App Store) supports a history of notifications, and additionally a rollup of all notifications while you are away from the computer. Unfortunately it requires Mac OS X Lion. You can get to the history right from the Growl Preferences.

Earlier versions did not have this feature.