There's some kind of a tool which revolves a face around a selected edge... I never got to use it but it might work...
Does someone know what I'm talking about?
It's a polygon modeling tool you can use on edges. perhaps on border edges.
Benny

EDIT:
Found it: Edit mash>Wadge face
You need to have face, or several faces selected together with the edges you want the geometry to be revolved around.
Might help you