Every rooted Android device that has a data plan can use the wifi hotspot feature for free. This allows you to share your 2G/3G/4G connection with other devices over wifi. With your device rooted you can provide free wifi to your:

-Laptop (Windows / Mac / Linux)
-Tablet
-iPad
-PS3
-Xbox 360
-PSP
-DS
-Any other device that can connect to wifi

How Much Will You Save Each Year?