MessageSling, one of the companies presenting today at the DEMOfall conference in San Diego, wants to make voicemail more versatile. It’s developing a service that allows people to receive voice messages as emails, SMS text messages or MP3 files, and conversely, to dictate messages in any of those formats.

Lot’s of companies are already something similar — including Jott and Spinvox — but MessageSling hopes to take it up a notch.

First, it’s easy to see how these service will all be incredibly useful. MessageSling, for example, turns your mobile phone into an all-purpose communication tool, allowing users to send and receive messages in any format they like. This service has become particularly relevant to users in California, where you’re no longer allowed to make mobile phone calls in your car — I know many people who do a lot of business through their mobile phones while driving to and from work. In fact, chief executive and founder Scot Junkin says MessageSling will focus its marketing efforts on the 15 states with “hands-free” mobile laws.

As mentioned, there are a number of other voice-to-text companies (my editor Matt Marshall has praised Jott’s convenience, for example) but Junkin touts the range of formats that MessageSling supports, as well as the ability to send, receive and organize messages, all through the company’s voice interface. SpinVox may be MessageSling’s closest competitor. Spinvox not only converts voice messages to text, but also lets you use voice messages to write blog posts and update your social networks. But Worcester, Mass.-based MessageSling has another advantage over SpinVox: It’s carrier independent. That means the service works with any mobile carrier and also allows you to transfer your voice mails when you switch carriers.

MessageSling is currently in a limited private testing mode, with plans for general availability early next year. MessageSling is privately funded, but Junkin, who was previously a software architect with Jingle Networks (provider of 1-800-Free-411) says he plans to go out for a small seed round soon.

Update: People can actually use SpinVox on any carrier through a product called uReach.

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