Quick note: I've been trying out a great new feature that Alltel has, Voice2Text. This service converts voicemail to text messages. I can see a lot of great mLearning opportunities with this. A service like Voice2Text allows the end user to choose how they are presented with the information. If they aren't in a place where they can listen to voicemail, it may be more convenient to simply read a text message.
Imagine pairing this with a voicemail distribution system. I'll start working on how this can be used on more specific learning applications.