Hi,
If you're good at coding, you can write an Outlook macro using the technique described at
http://www.howto-outlook.com/howto/saveaspdf.htm.
If you don't mind a commercial solution, I finished the Save-As-PDF add-in. You can find out more at
http://www.SperrySoftware.com/Outlook/Save-As-PDF.asp.
Hope this helps!
Mike Sperry
http://www.SperrySoftware.com
Find 37 Outlook add-ins that can make a difference!