I was recently state side, and picked up 2 of those Magicjack units.
Here is the basic information on it.
you get a little device that plugs into your PC's USB port. as soo as you plug it in, it starts to download software/updates. just wait about 2-3 Minutes.
You are not asked for credit card info, just name and address, tip: pick an address of someone in the USA that you know will be calling you a lot, this way it will be a local call for them to call you. also, it is not necessary for the other party to have a PC or magicjack unit.
You will be asked to pick from an Area code and the 3 digit prefix, for example mine starts 1-305-515-**** for Miami.
Into your MagicJack you plug in a standard telephone, I use a cordless one. no need for a VoiP phone like with Skype.
Once set up, you just dial your phone as you would in the USA, all calls to Canada and US are free, yes you can even call cell phones.
and the sweet part is that someone in the US can call you back using their regular phone or cell. they do not require a Magicjack, or anything special.
also if your offline or miss a call, there is an answering system, and the recorded messege is sent to your e-mail address as a .wav audio file.!
The draw back is that a call you make to someone local in the DR. would be seen by Magicjack as an attempt to call the DR from wherever you registered your device. the work around is, if that other person also has a Magicjack, you just call that number ( the USA Magicjack assigned number ) this I have tried, and works great. so in other words, if I want to call My uncle who is also here in Santo Domingo, I just dial his USA magicjack telephone number.
I havent tested this yet, but it should work, Some satellite receivers require a telephone line be connected ( specially multiple receivers ) the receivers "call and report" every once in a while. with magicjack on a pc thats always on, these receivers would be able to keep in touch.