Karma is a new pay-as-you-go mobile provider focused on data. The cool thing they do is, that by sharing your Karma hotspot with other Karma users, you both get free bandwidth.
Your Karma hotspot has Wi-Fi that’s open and branded for you (ex. John’s Karma). Anyone around can connect to it. When they do you’ll both receive 100MB of free data.
They claim six to eight hours of battery life, which is impressive if they can pull that off. Downside? It’s 4G only. This will make it perfect for high-density 4G areas and sitting at coffee shops, not so much for when you’re moving.