Ok, in order to bump this, and possibly generate some potential interest:
DVD Compliance:
For DVD compliant MPEG files, select the standard DVD parameters for your encoder, but change (modify, patch, etc.) the matrix on your encoder to use the KVCD "Notch" Quantization Matrix. This will enable play times of ~6 hours on a 4.7GB DVD(+-)R(W) media at a standard resolution of 720x480(576 ) Full D-1, Wide Screen encodes, or ~10 hours at a resolution of 352x480( 576 ) Half D-1.
So using this KVCD/KDVD encoder, you can fit ~6 hours on a standard DVD-R and the quality is AMAZING! Beter still is that is compatible with any DVD player that can play a DVD-R.
I believe the project is open source, so I really hope someone can port this over to MacOS X.
Here is a link to the specs of KVCD/KDVD:
http://www.kvcd.net/e107/article.php?21