Windows only: DemoHelper is a tiny (76k!) portable application that creates on-the-fly screen annotations, so you can draw all over your next presentation like a hyperactive sports announcer DemoHelper resides in the system tray, able to be activated and controlled by keyboard shortcuts, even if you're doing the drawing with a mouse pointer. You can draw freehand, use shapes like ovals and arrows, and change colours and objects on the fly. You can also set the screen to erase all the annotations after a set period of time, letting you move ahead without stopping to clear it away. There's also a zoom mode, also activated by user-defined hot keys. DemoHelper is freeware, Windows only.