*Smacks forehead!*
Karro, that's brilliant! I never thought to consider possible coriolis effects on the magma in the mantle & lithosphere. I'm going to have to go do some research on that tonight and compare with Earth's plates. That might make some interesting research, and it might make plate-creation a little easier in that it limits what currently are far too many options.

As for considering the individual parts' motion, like he says, I've found one of the most universal and quick ways to do it is to shade the plate boundaries in a certain colour, according to the type of interaction between the plates (convergent, divergent, subductive, etc). My favourite example of that is here: http://upload.wikimedia.org/wikipedi...etailed-en.svg

And I think that's enough thread hijacking out of me for today.

-asp