Have you ever been in a situation where you are boasting about Linux in front of all your windower friends and then after getting bored of your long lecture someone asks you to shut up and create a network with shared Internet so that they can work on their sucky systems(according to you) atleast then, leaving you staring at the roof wondering, "how the hell is this done"? . If yes, then here is a solution. Next time(if you get any), don't forget to throw it on their faces - how easily and quickly could it be done on Linux.
Most people, even many linuxers, think that managing networks on Linux is like walking on a bed of nails. You need to have good linux networking and command skills. That's because they are not aware of the fact that the network manager makes it tremendously easy for a regular user, with minimal knowledge, to handle various such networks.