Actually since you asked (a long time ago) there is one topic that I am interested in doing.

A Phone Blocker (by phone number)

I have been trying to find some papers on WindowsMobile.Telephony API abut having no luck. I can call a number but that is about it.

Any chance on doing a webcasts on that?

Also love the webcasts they got me up to speed on programming my first WM application with SqlCE.