No, I'm not on their payroll; I don't even want the freebies I'd get if I refer you, because it's too much of a headache. This is in response to Matt's post on this thread. Matt wanted to know how Ooma is going since I switched to it a few months ago. Ooma is a VoIP service that I switched my business landline to--they allow porting of landline (maybe cell too?) phone numbers, which is awesome because I've got business cards and stationary floating around out there with a phone number I've had for almost two years.
Ooma is great. I bought their previous-generation base unit on eBay for a little under $200 and sprung for their Premier service, which primarily does "simultaneous ring" much like Google Voice (without all the technical problems) to my cell and Ooma landline, and whatever other phones I want to add (you need an additional base unit to have it ring at a second landline). The Premier is $10 a month. If you don't need it--and I'll consider not renewing in a year--your phone service is:
$0 per month.
To answer Matt's question more specifically, the service is seamless; it works exactly like a landline, with the quality you expect from it. A bonus: you get your voicemails emailed to you as an attachment (you can call in for them or press a button on the Ooma unit too).
Caveat: I have Verizon FiOS, one of the fastest internet connections you can have. So I don't know how it will work on slower internet. I pay a little over $50 for the internet connection, but I write it off and I need it for my business.
The Ooma iPhone app, however, is not ready for primetime. So far, it sucks, and it doesn't support incoming calls. Perhaps they'll get that together at some point; it's optional, and paid for in addition to the other stuff--$10 for the app, 1.9 cents per minute. It's also possible that the wifi on my iPhone sucks, and maybe Ooma Mobile works better on a better iPhone.
The Ooma business model is another caveat: If no one springs for Premier, the business model looks a lot like a pyramid--it can't last forever without a revenue stream. But I suspect they have some tricks up their sleeve, and I further suspect that even the cheap Premier service is a very high-margin revenue stream--considering that Google Voice offers some of the same features for free.