CmdrTaco from the someone-is-gonna-love-that dept.
olsmeister writes "MagicJack is demonstrating a femtocell device at CES that will allow any GSM phone (locked or unlocked) to place free phone calls over the internet using VOIP. The device costs $40 and includes free service for 1 year. It supposedly will cover a 3,000 sq ft house."
We warn the reader in advance that the proof presented here depends on a
clever but highly unmotivated trick.
-- Howard Anton, "Elementary Linear Algebra"