Currently Being ModeratedNov 26, 2012 10:14 AM (in response to vlcu)
Keynote does not have this feature.
There are however numerous Mac applications that can do this, Google and see what is available for the spec of Mac you have
Currently Being ModeratedDec 7, 2012 9:10 PM (in response to vlcu)
I have been using PowerPoint, Camtasia 2, and a graphics tablet for preparing all my university lectures - since Keynote does not have the ability to write during presentations. That fact alone is crazy, since the whole point of a presentation is to "Present". That is like asking me to teach chemistry without a board to write on.
However, I just downloaded Omnidazzle today, and with a few modifications of their Hot Keys, the "Scribble" effect works perfectly with ANY program. You need to reconfigure the Hot Keys for Omnidazzle (Keynote uses all of the number keys), but once you do that it works perfectly.
AND, it is free!!
Good luck, I wish I had found this before I spent the entire summer building online lectures using PowerPoint for Mac. It's one of those ridiculous omissions in Mac programs that I miss once I switched all my work from Windows to OSX. As much as I love the elegance and fun of my Mac Air, I sure wish Apple software developers would take some cues from the PC world when it comes to business programs.