Well, kinda, but there are a lot of things to consider, and no method is
100% secure. Probably the most straightforward thing is to add a modify
password to the presentation and distribute it via autorun CD using the 2003
PPT Viewer. If your users must be able to open the presentation in PPT 97 or
2000, though, this isn't going to work.
Password protect a presentation
http://www.rdpslides.com/pptfaq/FAQ00038.htm
has additional information.
You know, I don't know exactly how that does work, now that you mention it.
Converting PPT to DVD might be an option, but be aware that it's not a
straightforward process, and you may not be happy with the quality of the
conversion. See Convert presentations to VHS or DVD video
http://www.rdpslides.com/pptfaq/FAQ00156.htm for more info on this subject.