Justin,

see
Convert presentations to VHS or DVD video
http://www.pptfaq.com/FAQ00156.htm

I do believe there is some free software out there if you look hard enough

Cheers
TAJ Simmons
microsoft powerpoint mvp

awesome - powerpoint backgrounds,
http://www.awesomebackgrounds.com
free powerpoint templates, tutorials, hints, tips and more...

HIJustin

Free :
You can use the free screen capturing codes like window media encoder
from Microsoft to save a powerpoint presentation as a video
presentation and burn the video to dvd with a burner.

Or you have a camcoder , just video tape it

However, the video quality can a big issue.

Paid:
Google "powerpoint to mpeg/dvd " and you will find a lot in the market.

And you may have a glance at PPT2DVD from
http://www.ppt-to-dvd.com

Rather than screen capturing , this tool encodes a powerpoint
presentation to a video one so that the video quality is really
improved.
Besides, you can also create  menus for the video on DVD.
If you are concerned the conversion quality a lot, paid programs will
be better.