*note: You can use any browser, but Chrome works so fast and is very easy to do for this tutorial.Free telephone service via internet connection at home, or at work. Sounds great? You bet! There's a lot of information out there, but my experiences are not available yet on the net. So I thought I'd help people Google current and informative hits by adding my two cents.
Great cost savings! Kiss your monthly bills goodbye. Just what is their business model? Apparently they are NFP, non-for-profit... NFP, wow someone really has a vendetta against plain ol' copper lines, POCs. (Getting your acronyms yet?)
Yes it's different than the VOIP (voice-over-internet-protocol) you've heard before. Unlike Skype or magic jack, you don't need a PC.
So unlike Vonage, there is no monthly fee. Except for overseas.
How do I distribute the phone lines outside just one room? The easy way is if you are wireless in the first place. But if you are wired, there’s a neat trick into using your in-wall lines. Plug the “phone” line into not just a handset, but into your home system. This will distribute the signal to the rest of the plugged in devices, but make sure you turn off your POC lines or you’ll get two dial tones, like I did!
It's not free yet. Gotta pay for the hardware. The start-up costs are quickly taken care of, after a few months. Less if you do a lot of long distance calls!
Now there is a regulatory fee. Wasn't there before. Considering getting the new Ooma Telo from an old hub, like I did? There are new terms and conditions that affect current and new customers differently. Now it gets complicated, but still not ugly yet. At least old hub owners like myself can get grandfathered to the extinct non-regulatory fee. Still $1 a month? Not great.
Got a special switching system at the office? Have multiple lines from an 10 year old+ system? Multiple locations, multiple businesses on site? I did. It’s been a headache. Please take into full account your topography, including if you have an alarm system in multiple locations. Test everything before and after, noting any differences in operation. I want to save money and am willing to put the effort, but you may end up becoming the target of frustration and complaints for implementing something all alone. Get a board and understand how this works and whose responsible for what.
The following clearly states that “each Ooma Telo can support up to 4 handsets.” It can, but it can’t. That is, not yet. They’ve been promising since it was announced.
Fact: The Ooma Telo can only support 1 Ooma Telo handset. That's right. Good thing I bought at Costco, so I return these extra handsets that’s been wasting my money.
Doesn't work with security systems that need POC lines. Don't ever expect it to. It may in time. After all, it can fax, but I couldn't get it to function at the office for our alarm system. So, we have a combination: Ooma for voice and POC line from AT&T for just the alarm. Therefore cost savings and recoup are slower, but over a stretch of time it pays back for sure. Just nice to know ahead of time.
Lies about the screen. Just look at the box or on the net, and you'll see it. Makes a difference because the letters are small enough, they don't need to be dark grey on light grey. Missed the boat here. Mistakes happen, PR slips and generates one thing while engineers are creative at keeping costs down and with it some usability. 
No handsets to plug in, nor Bluetooth for hands free around the house. Solution: plug in my old non-Ooma telephone handset system into the Ooma Telo directly.
Easy enough, but now you can't be hands free on that cool 2nd line you get with a premier service. In fact, the 2nd line is the only compelling reason to get the Telo Handset. You can get the usefully features like a hands-free in a multi-pack elsewhere. 
Ooma at least has this now as public knowledge, off their servers, not buried in a support forum. But please, don't put up with wasting your money on half-baked goods.
Troublesome registration of Handset to Telo.
You may have to re-register your handset:
(1.) Reboot the ooma Telo by removing the power, waiting 5 seconds and powering back up.
(2.) Hold the RED hang up button on the handset until the phone powers off.
(3.) Press the antenna key on the Telo for 5 seconds until it blinks.
(4.) Hold the left soft key and 0 on the handset and tap the RED hangup button.
(5.) The phone should go into registering mode and the Telo should pick it up and ask for pin.
Whacky Telo full reset: What happened to the old paper-clip push?
You could try performing a factory reset on the Telo, this will return all settings to default and wipe the previous handset registration, so re-registering the handset may then work.
1. Unplug the Telo power cord for 30 seconds, then plug back in.
2. As the Telo begins its startup, the 1 & 2 buttons will light up for a short while, followed briefly by the trash and envelope buttons, and then the bottom row of buttons will begin to flash in a scrolling sequence, which will continue approximately 28 times.
3. At the end of the blue flashing bottom row period, the Ooma logo will begin to flash red - IMMEDIATELY hold down the "stop" and "trash" buttons and the Ooma logo will alternatively flash red and blue. Continue to hold down the "stop" and "trash" buttons until the logo turns solid red and then goes out. After the logo goes out release the buttons and the Telo will restart.
You can see a poor quality video of the proceedure here:
With all it’s faults, I’m glad I got it at Costco just in case I need to return it. I’m thankful for having a “wired” telly line at the house and it doesn’t cost me anything monthly. At work, we ported the old number and are saving monthly. Now when budgeting, I don’t have to choose between internet or a telephone service. Fire your phone company! Save minutes on your cell phone plan, invest it. Whatever you do, be informed and know the weakness of the system along with all it’s strengths.
