On Wed, 8 Oct 2008 10:17:50 -0700 (PDT), "
wrote:

On Oct 8, 10:03*am, Wayne.B wrote:
On Wed, 08 Oct 2008 15:04:51 GMT, (Richard
...
I have had good luck with a pair of deviders.
...
How do you calculate great circle distances with dividers ?

Plot the LL's on a gnomic chart?

That might work as a piece-wise approximation.