The reason behind my question.  I wanted to make a simple light emitter that had a variable length cylinder attached to it, so I used the Pipe simple prop, changed origin :) , added 2 flat cylinders in the bottom.  One was the back, the other is a light emitter.  (all parts have "cast shadows" turned off)

The light seems a little more scattered than I expected, but I guess its OK.  I have not tried them with a figure.  Feel free to critique!  :)

Thanks again for the help!  Figured it'd be nice to see the "why" behind the question.