Use Mouseposé for training presentations.
If you give Macintosh training presentations or demos, give Mouseposé ($14.95) a try. Your audience will appreciate it.
With Mouseposé installed, press your defined hotkey, and it dims the screen and puts a spotlight around your mouse pointer, easily guiding the audience’s attention to an area of interest. Very useful when you are trying to point out a small-but-important detail on a large projection screen.
Mouseposé can also be configured to display a pop-up overlay on the screen showing any keys you press. A great feature for helping people understand when you are using certain shortcut commands, or say, holding down the Option key when clicking on a particular button.
This utility is simple, but it often gets a few "oohs" and "aahs" when Jason Hoppe pulls it out in one of his weekly mini-workshop classes.
Source: We first ran into this handy tool on Don McAllister's excellent ScreenCastsOnline. Another similar tool for augmenting screen presentations is OmniDazzle from Seattle's The Omni Group. Both are excellent. We use Mouseposé in our weekly mini-workshops largely because of the pop-up keystroke visualization feature.