I think Sharepoint has some workflow features you could check into, but I
don't think they let you "track changes."
There is a review feature in 2003 -- use File | Send to | Mail Recipient for
Review. Then when they email the file back, you can choose to review and
merge changes. I don't know exactly how this would work with Sharepoint,
though.
But mostly it's a matter of using comments. PPT doesn't really have "track
changes" features the way Word does.
I often use Acrobat. Convert the original and changed PPT files to PDF, then
use Acrobat's Document | Compare Documents feature.
