How to best implement portal physics with Bullet

[glutinous]

Hi,

I am working on a small 2D-ish game and would like to have it so that as the player crosses the left screen edge, half their body will appear on the right screen edge. The approach I am thinking of taking is to duplicate the body on the other side, but I am not 100% sure how I will keep their positions in sync - maybe with some kind of fixed joint.

Anyway, I thought I would ask here to try get other people's ideas on how to best approach this problem. As a reference, here is a video of the game I am working on:

http://www.youtube.com/watch?v=oK3q6q2KC4Q

Thanks!

-Steven