Check out these fittings: Sharkbite connection system.
My maintenance sales guy stopped in this morning and showed me this... and I'm still wowing over it:
http://www.cashacme.com/sbpush.php
No heat, glue or tools needed - and use the same fitting for whether you're using copper, cpvc, cts or pex - or even going from one to the other.
I will definitely keep a stop and a coupling in my toolbox for emergencies - and may very well try it on my next job that needs a fitting in a hard to reach spot.
I'm usually skeptical when I see something as amazing as this - and think "if it looks too good to be true then it probably is"
... so Tom, or anyone else who does plumbing: have you used them?. and are they as amazing as they seem?