These folks have a helpful online resource for Assistive Technology. There are links to commercial providers and reviews of some products.
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Here are a couple of other places to get AT information.
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Also, note that there are "Assistive Technology Initiatives" in almost every state. Following are a few state AT links from a file I have: Arizona ........... nau.edu/ihd/aztap/ Connecticut ....
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Delaware ........
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Georgia ...........
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Idaho ..............
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Louisiana .......
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Oklahoma ...... okabletech.okstate.edu/at/ Pennsylvania ..
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Rhode Island ..
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Texas ..............
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Virginia ..........
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Wisconsin ......
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Hope this helps a bit.