One of the most popular programs used in special education ans lower primary is "Clicker". I think I have already talked about EDword as a free replacement for it with the ability to make grids and change voices and controls.
One of the features of EDword and Clicker is that they highlight an speak the works on the page- giving students immediate feedback. You can now add this feature to plain old MS Word with WordTalk.
Word talk works as an add in and you can control what gets read and when - with controls for words, sentences, paragrams and selection. It even has a record funtion that records the speach into a MP3 or ogg file - good for getting people who don't like speaking doing a podcast.