Vonage is starting to look like the ma-bell of VoIP. It’s not that there isn’t competition — there is, but they just don’t have the profile that Vonage has. It looks like Vonage has picked up the early adopters, now they have to start converting others.
The market seems to have three fields: computer-to-computer only, software client with POTS bridging, and hardware client with POTS bridging. I don’t much care about the computer-to-computer systems, AIM and iChat take care of that well enough. I need to call phone numbers on the standard phone network and I want a real phone number for people to call me back on.
Mobitus and Nikotel seem to be in the software to POTS business. SIPPhone claims “use your normal phone” and provides a telephone adapter, but it’s a UK number (which could be cool). Broadvoice so far distinguishes itself by offering the first WiFi VoIP phone that I’m aware of.