Go2Linux posted a tutorial about sharing your 3G Internet connection over wifi (Linux / iPod Touch)

I was in a situation the other day, where I needed to connect my iPod Touch to the internet but there was no wifi available so I think about using my 3G data plan. I have a data plan with my Laptop, I use a Huawei E156 B, to connect my laptop with the 3G network.
Of course I have a wifi network in my Laptop too, so what I needed to do was:

Connect my laptop to the 3G network
Enable my wifi network in Ad-Hoc mode
Configure DHCP server to give IP to my iPod Touch
Enable IP forwarding in the Linux kernel
Add the needed routes.
Add needed IPTables rules for NAT

  Share your 3G Internet connection over wifi (Linux / iPod Touch)