However, the "Magic Jack" also supports the sound features in the computer, so there is no need to lug around a telephone set. It works fine with a computer headset with boom mic or even with the built-in conference mic and speaker found in many laptops. You can select whether to use the RJ-11 phone jack or the computer headset by checking a box in the "Magic Jack" software screen display.
3) The "Magic Jack" installs no permanent software on your computer. It is recognized by the computer's Windows operating system as if it were an outboard USB drive and the computer then runs the "Magic Jack" software from that drive. This is a nice feature because it means that you can plug the "Magic Jack" into a shared computer (public library, internet cafe, friend's house, etc.) where you otherwise would not be allowed to install your own software and where you might would be at risk of forgetting to remove your personal software when done.(Please note that there are many other security issues of using a computer which you do not control but the "Magic Jack" design provides some mitigation of the risk.)
As someone pointed out, it does take a couple of minutes for the "Magic Jack" to start up when first plugged into the computer. And, while the company provides some moderate level of service, handling administrative things like changing your number to a different area code if you move, dealing with a lost or broken device, etc. could be a hastle.
"Magic Jack" as a business is about 25% technology and 75% marketing. Their TV infomercials are gung-ho and their web site has the look and feel of the Home Shopping Network cubic zirconia blow-out.
As near as I can figure out, "Magic Jack" is a very ingenious way for the parent CLEC to sell its excess capacity. Keep in mind that a faciliteis-based IXC CLEC has a high fixed cost and very, very little incremental cost for handling calls. "Magic Jack" has nice front-end revenue of $40 for the device and first year of service and then an automatically (unless cancelled) renewal providing a predictable future revenue stream. And, while paying a big upfront fee for anything always worries me because of the number of take-the-money-and-run businesses which fold, it's of little concern here because the low $40 price of the "Magic Jack" is equal to a month or two of conventional phone service and may have an even faster payback if one is used to paying for IXC logn distance calls.
Disclaimer: I have no relationship to the "Magic Jack" company and speak only from my personal experience as a customer who acquired one of their devices. Having read some of the stuff posted on line, your experience may be different or may be similar.
Regards, Will