You've heard of FreedomPop, right? It's the Clearwire-powered 4G service that gives you a "free" mobile hot spot and 500MB of data per month, with the option of earning extra by referring friends.
FreedomPop is still in beta, but already it has some interesting competition. Karma offers a Clearwire-powered 4G mobile hot spot with 1GB of free data, with the option of earning extra by referring....strangers.
It works like this: You pay $79 for Karma's compact, 2.1-ounce hot spot, which can share its 4G goodness with up to eight devices. After you activate … Read more