I don't know if it has already been done, so...
http://www.box.net/shared/om39g34t34It's fresh and homemade in VB.NET using a bit of api calls.
Hold your left mousebutton (or your IR-pen button) for .4s to right-click.
You can easily use it with your whiteboard.
Best of all, it's simple and convenient.
Requirements:
.NET Framework 3.5 (Don't know if earlier versions work)
EDIT: Fixed some bugs. Download again to see for yourself.