Magic Jacks are a phone connection that works in conjunction with your computer. The new ones that they have now can actually be connected without a computer, at least I think that is what I read. It has been quite a while since I had mine; but it is one of the cheapest ways to have a phone, since it costs about $49 for the Magic Jack and the first year of service, and then $20 per year after that. You could call anywhere with it, at least in the United States, and even take it with you when you traveled. If you had a laptop and could connect to internet, then the Magic Jack would work. The connection was not as good as on a regular phone line, and it only worked when connected to a computer that was turned on. So, if the electricity went out, or the computer died, or was even shut down for the night; then you did not have a phone anymore. Now, more cell companies have unlimited calling plans, and you can call anywhere and talk as long as you want; but back when I had the Magic Jack, cell phones were still pretty expensive if you made very many calls and paid by the minute for each one. Now, I pretty much use my cell phone for everything; but the Magic Jack was pretty handy when I had it.
I didn't realize you could take the Magic Jack with you like Vonage. Where I live, cell phones barely work, so a home phone is necessary. Although my 'cable' provider offers phone, I cancelled that a couple of years ago, and went with Basic Talk (available at Walmart) for my home phone. It's around $13/month with taxes, which is the best deal I've found. It's amazing how much technology has changed over our lifetimes!
When I said that you can take it with you, I did not mean that it works like a cell phone that you can carry around and use anywhere. But you can carry the Magic jack connector along with you if you are traveling. It does need a regular phone as well; so you would have to either carry your own phone to use, or be able to plug a hotel phone into the magic jack. Sometimes, the hotel phones only work with a special dial-out number; so I am not sure how well that would work with a magic jack. Actually, even my iPad will make phone calls now. I have not tired doing that; but it is one of the functions that it has. I think that if you only need to have a home phone that you can make calls with as much as you want , then you can't get anything cheaper than a magic jack.
I use skype for my home phone. The skype is on my computer and I pay around 20 for 3 months of service. I have even been able to connect skype to my cell phone.
I think I understand what you meant, From what I understand, it's an adapter-type product that you plug in, that works using your account/phone number, whether you're at your home or a hotel, or I guess maybe someone else's home? I think it's a form of VOIP, which is what I have through BasicTalk, although I don't believe Basic Talk is portable in the same way as Magic Jack.
I had a magicjack. There wasn't much magic to it. The connection was always terrible and people couldn't understand me. Some of that might have had something to do with my slower internet connection. I have since increased my speed, but I ended up getting a landline again. It's just easier. To use a phone strictly through a PC, I'd try Google phone.