True Confession time:
I actually decided to try Magic Jack. I never, never, ever buy anything from TV, but I felt that, worst case, I wasn't risking very much. I have Optimum Online cable, so that is what it's going through, but it's entirely independent of the cable company.
The instructions are that you plug it into your USB socket and plug in a standard phone on the other end. You don't load any software or set anything up. I bought a $6.99 phone at Walmart to hook into the other end (just in case it might fry my electronics, which it turned out it didn't).
I plugged it in like any hard-nosed, experienced, IT-trained person, knowing it would be foolish and ridiculous. You have to figure that it has to be set up for morons, probably morons who wouldn't know any better if it had lousy sound or jammed up their PCs with ads or used up their internet bandwidth with tattletale cookies and other consumer monitoring programs.
Disconcertingly, it works great. You actually get a dial tone. It can be unplugged and replugged at any time and resets itself. You get your own phone number. It's very simple to put your address into the 911 service (and free). The sound is very good and crisp (and no interference), and after the initital purchase (which wasn't very much), you can get all the phone time you want in the US and Canada for $20/year. Period. And if you know someone overseas and they also have a Magic Jack, those calls are covered by that $20, too (if I understood the documentation). Otherwise, you can purchase a cheap international package.
You can use your PC for other things at the same time. And it hasn't eaten up my internet bandwidth or jammed up my PC with ads.
I'm sure there are others out there as well, probably as good or better and/or as cheap (I'm not trying to sell these, after all, this is just the one I have experience with).
Up until now, I had been using the cell phone for long distance, but there are often issues with volume, interference, batteries running out, or signal fading in and out, especially when talking to older people on the cell phone. For the quality of the signal, I don't at all mind being tethered to the PC. A wireless phone handset would work, too, but I haven't bothered to try one.
So, I have to vote favorably for VOIP. Can't use it when the power's out, but for quality sound transmission on long distance calls, it's as good as a hardwired phone line.
Best wishes,