Netbooks are very useful devices, not just for web surfing and looking at your email for for all sorts of different purposes, some more obvious than others. These devices are all about mobility, but while you are out and about there could be situations where setting up a wireless network to connect a group of machines might be handy and of course Internet access makes this even more useful. Maybe you have a device you would like to use with the Internet while you are away, but it only has WiFi connection (e.g. some portable media players like the iPod Touch) and you cannot plug your 3G mobile broadband modem into it. As long as you have 3G coverage you can have a WiFi hotspot wherever you go, and you don't need to bring a dedicated router as a netbook powered by Ubuntu (or Easy Peasy) can easily fulfill this function.
Mobile broadband is becoming more popular now and many people are enjoying the convenience of being able to get broadband internet from a wide variety of locations. Both pre-pay and contract options are available on connections and the cost of using this service can be very reasonable. A lot of contracts are based on the idea of paying a certain rate for a set amount of data, for example £10 might buy you 1GB of data, but go over this allowance and the surfing could start getting a bit more expensive with each megabyte being charged separately at a high rate.