Most folks who do presentations know how much of a pain it is to show Windows or applications and have the screen visible to all. Even in a small room, it can be very tough. I'm presenting this week in Kuala Lumpur and want to show OCS's Snooper tool, which is pretty tiny at the back of the huge ballroom. Then I found ZoomIt, a Sysinternals tool that is excellent. A very small application, ZoomIt allows you to blow up the window on screen and enables you to draw. There's also a cool break timer feature that I'm finding VERY useful already.
You can download ZoomIt from Microsoft's web site. Oh - and it's free - very nice!!