This excellent idea from Microsoft UX Evangelist René de Paula Jr arrived just 1/2 a day too late for me to try it out at Code Mash, but I will do so at my next opportunity. He suggests placing a Microsoft Tag encoding my VCard as the final slide in my presentation; which I think is nothing short of brilliant.
(note, using the gettag phone application on the image above will, in fact, add my contact information to your contacts).
It will be interesting to think about how these tags might be integrated into Silverlight applications.