I use and love Growl! and especially the GrowlTunes plugin which shows you track info when iTunes song changes.
What really annoys me, though – when listening to radio stream, it shows “(null).” instead of track number and there is also only radio name, not song name in the recently played songs menu.
I created small patch. Or download patched binary. Simply unpack and put into your Applications folder (replacing original GrowlTunes if present).
This is how it looked before:
And this is how it looks like after patch: