OK I'm really stuck with this. Maybe I'm trying to achieve something different and barking up the wrong tree. I have 49 gb of mp3s, but only a 40gb iPod (I think about 37gb in reality). Why can't I just keep deselecting tracks/albums/artists until I reach my target? Isn't there a little counter anywhere? The reading at the bottom always gives the total amount in the library, rather than selected tracks. This also applies if I create a smart playlist, and why would I want to set the limit to 100gb? Shouldn't it be the same as the capacity of my iPod?