Cell phone data plan

I don't see why not. If you can use Skype you can use Magic Jack as they are pretty close to the same technology less Magic Jacks DTMF telephone interface.

Have you ever used a Magic Jack? The audio is clear, but there is a lot of latency.

Yes, my dad has one. He is on high speed cable internet and I didn't notice very much latency with his setup. This was about 2 years ago and MJ wasn't nearly as popular as it is today. He doesn't use it much because he always has a cell phone. I wonder if whatever MJ uses to connect to the telco's is bogged down now?

Magic Jack requires a minimum upload speed of 128 KB/s (or kbit/s or kbps). There is no minimum requirement for download speed.

That's what they say. However to me 128 KB/s is kilobytes per second.

Anyway

Test your upload speed at

An IPhone at 3G was rumored to do 225 kbps upstream.

I only use it for a backup becasue of the latency problems. I have between 7 and 10 Mb/s data rate downstream and 1.5 to 2.5 upstream. I've had it about three months. Also, I'm not sure if it can handle the QPSK modulation.

One other problem: Magic Jack installs some software on a PC the first time you use it. It may not work with a cell phone.