This is a very good tool for recording a voice message. All you need is a microphone! There's no time limit which is a bonus. After recording your message, you can easily send it to a friend via mail or post it on your site. As a language teacher, I could see this being a great tool for getting students to send specific messages to eachother or to their teacher. Some ideas that occur to me could be the following:
A Dictation: - students could send messages to eachother. The receiver could listen and write down the message.
A Greeting: Students could send greeting messages to their teacher or introduce themselves at the beginning of the year.
Narrative Stories: Students or teachers could record themselves reading short narrative stories. The other students would listen to the story and 'listen for specific information'.
Pronunciation: Different accents could be recorded and students would have to listen and try to identify them.