I used vozMe to change text into an mp3. My phone speaks to me in a female voice when I have an email or message.
email = "You have new mail"
texts = "You have a new message"
Easy to distinguish my alerts. Sounds cool too. I plan to make more sometime as I find apps that allow custon alerts.
http://vozme.com/index.php?lang=en
EDIT: Forgot to download the mp3 you need to use the patch that dl's rather than stream.