Tim K,
What everyone else said.... but also.... you may want to check the "number
of pixels" in your pictures before inserting 500.... as it may make your
powerpoint file unmanageable.
see
Why are my PowerPoint files so big? What can I do about it?
http://www.rdpslides.com/pptfaq/FAQ00062.htm
You need to think about pixels!
Cheers
TAJ Simmons
microsoft powerpoint mvp
awesome - powerpoint backgrounds,
http://www.powerpointbackgrounds.com
free powerpoint templates, tutorials, hints and tips etc