Softboy.net On-screen-keyboard can be useful if you have mobility impairments, if you are using a tablet PC, or if your keyboard goes down. And it can works well on touch-screen. This a demo keyboard which includes the main keys on a normal keyboard.
Touch-It is a powerful set of tools to build on screen keyboards. You can type right away using the preset templates (and word completion) or create your own from scratch. Special keys available to interface with your app. Multi monitor supported.