I have few experience with lipsync, twice in max and once in maya. In Max I got my hands on a very easy to use script. I don't have it anymore, but I doubt it's hard to track down. You simply pose one side of the face and hit the mirror button and it would create a mirrored version. I've been told maya out of the box has a…
The mirroring script for Maya is called abSymMesh, it comes with Art of Rigging Vol.1 book, and is really useful. Can be also found at HighEnd3D: http://www.highend3d.com/maya/downloads/mel_scripts/modeling/poly_tools/abSymMesh-2830.html