The latest one is a voice-twist on SMS technology. This technology called Rapid Message Service, or RMS, that allows any cellular subscriber to easily send a voice message (using SMS technology) to another subscriber regardless of their handset or network operator. No more awkwardly typing text messages using the phone keyboard. This service comes from a company called HeyAnita.com which has been in speech recognition software business for sometime.
Interesting idea, though I wonder why not just use voice mail, or simply make a phone call.
taken from gigaom.com