As Austin said, you don't need to do anything special (especially if you
don't mind typing in the address). For example - open PowerPoint; on your
title slide, click inside the title placeholder and type the following
(notice the "space" at the end): "
www.pttinc.com ". The space added to the
end recognizes it as a URL address. Go into slide Show Mode, click the
link, and you have just gone to my site (sorry for the advertising).
Clicking the "X" at the top right closes IE and takes you back to your
presentation.
Hope that helps!