If you have difficulty speaking but have fairly good handwriting, you might consider using the Herbi Speech Assistant software. This software was written by Todd Landstad, for someone he knew who had Motor Neurone Disease, (also known as ALS). Todd worked for a number of years in the Tablet PC team at Microsoft. The Herbi Speech Assistant software runs on Tablet PCs or Ultra-mobile PCs, (UMPCs). UMPCs are less expensive than Tablet PCs and are more portable.
With the Herbi Speech Assistant, you can use a mix of handwriting and phrase selection to build up a sentence that you want to have spoken. For example, you may have the phrase "Could you get me" in a list where it can be quickly selected, and then you might handwrite the remainder of the sentence. The software will try to anticipate what you might be writing as you start to write it.
To learn more about the Herbi Speech Assistant software, click Herbi Speech Assistant.