Ftraylor,
Insert the jpeg as the background (Format - Background - click on the
arrow - choose fill in effects - tab picture - select picture - browse to
the folder - insert - OK, apply) in the master of a new presentation, save
the lot as a Powerpoint template. Don't know though if the quality will be
up to your standards. You could also insert the picture directly onto the
master and direct it to the background.
Luc