I've looked at GoodOS (gOS) before in two other posts: The Netbook Market Booms with Linux Onboard and Three Linux Distros to Watch and Use but now they've taken the lightweight operating system (OS) one step further with Taiwan-based manufacturer GigaByte.
The GoodOS team created a very stripped down, browser-based mini OS, named Cloud. Every netbook comes standard with Cloud and Windows or Linux as its locally installed "heavy" OS. You can boot directly to Cloud, use the Internet, rich applications, online applications, etc. and with a single click, you can boot to your "real" OS--either Windows and Linux.
The advantages to such an operating system such as Cloud are to extend battery life while unplugged, speed boot times, and to avoid locally installed OS problems such as viruses, spyware, and adware.
How it works: The netbook boots the Cloud OS in the foreground within a few seconds and allows you to get started right away. In the background, either Linux or Windows boots so that when you want or need to, you can switch.
Within the next couple of years, you'll see more manufacturers creating this same kind of environment for regular notebooks, desktops, and possibly even server systems.
I would like to have one of these Cloudbooks for myself since I spend most of my time in either a browser or a word processor. [Note to GigaByte and GoodOS: I'll be glad to supply you with contact details so that you can send me one.]