fascinating!
I would like to achieve exactly the same, albeit forwarding the
notifications to a custom service of mine.
I'm intrigued as of how you managed to get the notifications from
growl... is it in some sort of log file, or are you using a network
protocol?...
anyway I might be interested in using your code, if it's open source
of course, as I'm also in the process of self-teaching objective-c :-)