You can also do voice blogs or have a voice message service for free on your blogs. Sounds fun! I am trying to figure how it works!!
Info from their website:
Snapvine brings voice and mobility to social networks. Using the snapvine Voice Player, users are able to safely communicate -- in their own voices -- with their online community. Unlike with other solutions which require expensive handsets and complicated downloads, snapvine's easy-to-use products work on any cell phone, with any carrier.