Posted for "Alan K. Adamson" <aadamson@highrf.com>:

 Just was doing a little research.  For these "push on fittings", go to
 www.mcmaster.com and search for "instant tube", you can pick the material
 and they even have some that "snap" together to make more complex shapes or
 manifold.
 
 Now if I can just remember to find this message when I need them... /;)
 
 Alan