Oh Boy, here is an update to this post...
Apparently Cubic Telecom provided the wrong prices to David Pogue, so the savings aren't as much as 90%. Me thinks that the company doesn't have its act together, but I'll let David tell the story...
Setting the Record Straight on Cubic Telecom’s International RatesAn excerpt:
"On average, then, it looks like the Cubic card saves you between 25 and 75 percent off the big carriers' rates. Not 90 percent, as I reported.
(Besides: As I noted in the column, if you call overseas a lot, you can pay another $5 a month for a special world-caller plan that gives you lower rates.)
Overall, though, I feel a bit manipulated, since the primary virtue of the Cubic phone was its low rates.
I'm not exactly sure how the problem could have been avoided—in 20 years of reviewing tech products, nobody has ever deliberately misled me on hard facts like prices—but I thought you should hear about it from me."