Making a mash-up on the cheap? (TONIGHT?!) + GarageBand/iTunes question

My kids' friend wants to take a number of segments of different songs and stick them together for a talent show school thing.

Phase 1 is TOMORROW-nice to have advance notice, eh?

Let's presume I have all the songs in iTunes.

Note: I'm on a Mac. PC is available, but no songs on it.

I know I can set iTunes to vary the start and end times of the tracks. So in the worst case I could make copies of the songs, set the start and end times, stick them in a playlist, and play them from an iPod. Of course, there may be a gap between each segment, and for the actual talent show they may require a CD.
?If you set different start and end points in iTunes for the song, do they burn to CD like that?

--> I'm wondering how to make a kind of mash-up CD from tracks I have.

Can GarageBand do that? Or is there some freeware that will let me blend tracks together?

Suggestions?

(Phase 2, the actual talent show, is in about 3 weeks)

 

I use Audacity. It's free.

I used it to blend the mono and stereo versions of 'Baby You're A Rich Man'.

Take a listen:
http://www.youtube.com/watch?v=W_0RXykIn24

 

Use GB,import from Tunes,mangle and re export back to Tunes.

Chip your version seems to have doubled the tape flutter and little else?