A friend who is also a Vegas user asked me if I knew of plug-in products to simplify the process of making 'slick' photo slide show productions in Vegas. I don't often do this myself so I didn't have any suggestions. Any ideas?

VMS 10 has a built-in feature for the initial layout of slide shows. It doesn't look as powerful as some of the other products, but it does give a decent start. The video is on this page, lower portion:

Vegas Movie Studio HD Platinum 10 Video Editing (http://www.sonycreativesoftware.com/moviestudiope/videoediting)

Hope this helps,

Excalibur, Montage Magic, Ultimate S (Pro and Lite) and Mayhem and four that come to mind right away.
jetdv.com (http://www.jetdv.com/vegas/forum/index.php) for the first two and VASST.com (http://www.vasst.com/) for the second two.
Demo versions are available for all of them.
Please note that Vegas Pro is required for all of these as they rely heavily on scripting, a feature not available for any Movie Studio version.