Looks like Ribbit is chasing the GoogleVoice market with their launch of Ribbit Mobile, in beta, today.
Ribbit Mobile is built on the Ribbit Platform, that BT paid over 100 million dollars for. Key point is the service is free (for now) but has a monthly value of $30.00.
From the announcement the key feature that Ribbit Mobile offers vs. Google Voice is Voice Memos. Here they are going after the market that JOTT has staked out a while back, and going farther back, where both MobileWord and SpeechMachines both tried and failed.
Once my account goes live, I'll have a better perspective on just how much different, or similar to Google Voice Ribbit Mobile really is.
One of the more interesting features is the promise of a softphone, that is coming in 2010.
Also, the capability to drop and add phone numbers at will, makes this a lot like what TalkPlus tried to do a few years back.
Look over the feature set and see how Ribbit Mobile works.