As far as I can tell, that is correct, you cannot use it without a computer. From the MagicJack website; "you need a computer running Microsoft® Windows (XP, Vista, 7) or Intel-based Mac® with a high speed Internet connection and, if you purchase the magicJack device, an available USB port. Bear in mind that the magicJack device and/or the Software are dependent on these requirements..."
found here http://www.magicjack.com/intl/en-ca/tos/
I've been trying to figure it out since Anonymous asked about it originally. I still am not able to come to grips with what it says - very confusing to me. I've asked a few of my friends but they are as baffled as I am. The website says yes, you can use it as a stand alone unit but does not adequately (for my understanding) explain how. The few pictures I've seen of the unit show either an ethernet cable or telephone cable plugged ito it so I just don't know...
Wow, I just found this... took a little more effort than I had expected (or wanted) but here's what MJ+ says for use without a computer
"Using magicJack PLUS without a computer
1. Plug the magicJack PLUS into the power adapter that has been provided
2. Plug the Ethernet cord that has been provided into the magicJack PLUS
3. Plug the other end of the Ethernet cord into your modem our router