Here is a simple way to breakout Compilations (collections of on your iPod
In iTunes, navigate to your compilations and set the Composer for all those tracks to "~Compilations" (do this by hitting Command-I to open the info menu and set it there; don't use the quotes).
Then on your iPod, add Composers to the top-level menu and the Composer named ~Compilations should be first in you list.
Mac OS X Hints
http://hints.macworld.com/article.php?story=20040720193816819