A bit like in Yugma.com... where you could "doodle" anywhere on the screen.
I realise you could point to things, even open up paint or something to doodle.. but again like in Yugma, you can easily/quickly draw elipses/boxes etc to have the realtime interaction with the other parties.
I like SharedView though - the other apps I have tried do work, and have very good points, but being Microsoft it seem to integrate nicely - or at least it looks like it will integrate with most of the common MS apps.