The music that you rent...
No... you can't use the music that you
rent from Apple in Toast, or for that matter any other application other than Apple's apps.
I say rent, because you don't own that music... sure you paid .99 for it, but you don't own it... Apple does... and according to their terms of service agreement which they can (and do) change whenever they want... you can only burn it with their applications.
If you owned it, you could do things with it that you could do with any other song that you purchased and owned, like a CD that you buy from the store.
So... if you want to really own your music, buy CDs... if you like renting, buy from iTunes.
BTW - if you're looking to use your rented music in other apps without burning a disc and wasting it... here's some options...
1. Use Audio Hijack... it saves a perfect copy of the audio down on your desktop without any loss of quality (burning a CD and reripping would have loss of quality)
OR
2. Open iMovie, create new project, add a single photo to the project, add a purchased music track as your soundtrack, go to Share menu, save out project as QuickTime movie, go to advanced options and save out as AIFF audio, then drag/drop into iTunes
BTW - for the poster who hoped that iTunes added CD-TEXT... forget it... CD-TEXT is a burning related thing, and Apple's probably taken burning as far as they plan to... they don't want you to burn discs... that's sold "old fashioned"
It's pretty obvious that they want all of us to go out and buy 60GB iPods as the way to store and transfer and watch/listen to our video and audio.