I am not terribly sophisticated technically, so I would never do this. But if you so desire, and are willing to sign up for a free account, you can turn anything you have on CD into a ringtone for your mobile phone at phonezoo.com.
I'll bet some of our DRs could up with some creative uses of show tunes!
I have a program (and I had to buy a specific data cable, too) that can upload any .mp3 or .mid file as a ringtone for my cell phone! That's why I wanted this particular phone. Last year, when
The Last Starfighter was part of a new musicals festival reading (it was fabulous!) in Issaquah, WA, I downloaded a couple of tracks from
TLS original cast recording as a tribute to Fred and Skip!

I also have a song of BK's on my phone (or is it Guy Haines singing??). What I have now (and have had the longest) is the opening 30 or so seconds of the overture to Sondheim's
Merrily We Roll Along.