Pinger is doing the rounds of Twitterland at the moment. It’s a service that allows you to send voice messages to one or a group of people anywhere from a local number. It’s not new to be able to do this on some networks and some phones, but they’ve made it easy and cross-network and country.
They’ve presented it as a kind of voice-based text-messeging, but I can imagine it might get used like Twitter too.
On the plus side, I can imagine it would be very useful if you were trying to organise some kind of gathering, either impromptu or making changes to a previously organised one.
On the negative side I can imagine an increase in voice spam from either your friends or marketing baddies.