Came across a great accessible site today for the Food Standards Agency: http://www.food.gov.uk/
At the bottom left, there is a Listen to this site link. This led to a link that looked like this:
An exploration of the DixerIT Plus logo led to this site: http://www.championinternet.com/dixeritplus/ and http://voice.phiware.com/
http://voice.phiware.com/ is a hosted solution that gives any website text to speech functionality, making it more accessible. The voice is very human compared to those I've come across before. I was impressed.