Found some free simple businessman/business woman silhouettes for use in PowerPower (Presenter) and other programs (like Storyline) here:  http://www.indezine.com/mailers/sent/20120529.html  (also a nice review of one of my favorite graphics tools, Xara).

Of course, there's also the excellent (and more varied) ones that Jeanette provided to us over a year ago:

http://community.articulate.com/downloads/p/13060.aspx

http://community.articulate.com/downloads/p/10153.aspx

Thanks Gerry - needed some more - I've used all of Jeanette's ones to death!