David Rowe VK5DGR and Rick Barnich KA8BMA have been working on an implementation of FreeDV (HF Digital Voice) in a hardware mic, for any HF rig. Previously, FreeDV required a PC to process the incoming and outgoing audio.
FreeDV is completely open source and the software is available for Windows, Linux and Mac. If you already run other digital modes, such as PSK31 via PC, your station can already do FreeDV.
Check out the SmartMic Announcement: Introducing SmartMic Ham Radio Digital Voice
Visit freedv.org for more information on FreeDV.