As long as you don't use any of the new animations you will be fine. There
is a feature in 2002 (assume it is also in 2003) under the "Tools" menu,
select "Options", click the "Edit" TAB and at the bottom, check the disabled
features you want to disable (at least the "New animation effects"). New
effects will not prevent you from viewing a presentation in 2000, but the
animations will not occur since 2000 doesn't know what they are. The
objects will merely appear on the slide when it is presented (no
animations). The password feature uses a new encryption so if you password
protect your 2003 PPT file, you can not open it in 2000 (can't recognize
password encryption method used). The "Multiple masters" allows you to have
two or more separate design templates in the same file (new in 2002 and
2003). You can leave this unchecked because you will still be able to view
the multiple designs in 2000.
Hope this helps!
