usb tethering

connect your phone via usb to your computer. your phone gets charged via your computer, while your computer gets the internet via your phone. win-win synergy!

enable tethering on your phone.
Settings > Wireless & networks > Tethering & portable hotspot > USB tethering

if you don't see the above setting, your mobile phone provider has probably disabled it. use an open-source rom, like cyanogenmod.

load usbnet module
# modprobe usbnet

verify usb interface
$ ifconfig -a

modify network interface configuration
# vi /etc/network/interfaces
iface usb0 inet dhcp

bring the interface up
# ifup usb0

et voila!