Want to have a voice speak your last tweet on Twitter? You can with Parrotweet.
To use Parrotweet, visit the site and click the Login button. You will be sent to Twitter to varify and connect the Parrotweet service to your Twitter account.
Once you click "allow access" on Twitter, you are sent back to Parrotweet to post an item.
The post page is very similar to Twitter's page, you have an edit box for the tweet, a Parrotweet button to post the tweet and a logout button to use when you're finished.
Type what you want to have read and Parrotweet will present you with a page including the text of your tweet and it should speak the tweet as well.
You will notice that a tweet with a URL has been posted to your Twitter account. Followers may click the link to have that tweet read aloud.
Click this link to give http://parrotweet.com a try!