I was about to ask the same thing. I also want to know if DISers have used
Skype too, or instead. And if you've used BOTH, which do you prefer?
There are threads on the Fatwallet.com board about both & the reviews were mixed.
There even is a whole forum for
Magic Jack users:
http://www.magicjacksupport.com/
I'm kind of leaning toward getting
Magic Jack as it is cheaper than
Skype, at about $3/month, comes with a phone number & voice mail vs.
Skype which charges about an extra $8-10/mo to include those features.
But, from what I've read so far, there
are bugs with MJ, as there is no way to uninstall it off your computer,

or go
back to a previous version if the upgrade doesn't work, without manually going into your registry and bit by bit, taking out each component. Not something for people who don't know how to work computers should do, as it can screw up the computer.
BUT, people who have had very few problems, say it is great! You do need a PC with Win XP or better, AND high speed internet, or the complaints are many, as quality is bad. (This is with both
MJ & Skype.) Everyone has said both services are NOT a replacement for a regular phone service, as quality & connection are not consistant or good. But, as a back up to a cellphone which eats minutes, or a replacement to landline long distance phone charges, it's okay.