Here's the links to two of the products I used this evening during the keynote demo presentation. Many had asked where to find them or how to enable the system level setting:

MousePose: essential tool for doing product demo's or presentations -- hilight your mouse location to make it easy for folks to follow!!!

http://www.boinx.com/mousepose/

Salling Clicker: control your Keynote or PowerPoint presentation with a bluetooth cell phone (mac or windows). You can control other cool stuff on your mac too!!!

www.salling.com

OSⁱ X system feature to Zoom In on the fly: a great way to make it clear to viewers just what you want them to look at on screen

open System Preferences > Universal Access > Seeing tab: turn ZOOM on

press Command + Option + = to zoom in to any spot on your screen
press Command + Option + - to zoom out

Here's a screen shot that shows the MousePose Effect and where to click to turn on system level zooming: