Dasher is free and fun...
Try Dasher in your browser right now!
http://www.inference.phy.cam.ac.uk/dasher/

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Click-N-Type / Free
http://cnt.lakefolks.com/

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More videos of people using Assistiveware products here:
http://www.assistiveware.com/videos.php

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TextAloud uses voice synthesis to convert text into spoken audio. Listen on your PC or create MP3 or WMA files for use on portable devices like iPods, PocketPCs, and CD players.
http://www.nextup.com/

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Windows 98 & XP has a built in onscreen keyboard in accessories > accessibility.

It's set to open when pc starts up & hover to click keys, there's even shortcut keys like an ordinary keyboard.

I now use this in conjunction with a free dwell click program called point n click get it here
http://www.polital.com/pnc/ or click aid http://www.polital.com/ca/ they also have click n type http://cnt.lakefolks.com/ with word prediction, if you use this you also need the library to match your language again it's free.

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