I have the iTunes screensaver set as my default sceensaver in OSX. All my music is located on a network share accessed from my MacBook. When I'm on the network the screensaver works fine, but when I'm away from home, I just get a black screen saying that my iTunes library contains no artwork.

This is because it can't reach my files when I am away from the network. Does anyone know a way to cache the artwork so that it will work even when the mp3s are inaccessible, or suggest an alternative to the iTunes screensaver which looks the same but works offline?