With market and technology shifting from notebooks to its light yet powerful cousins, the netbooks, we're gonna see alot more people asking about how to get their favourite Operating System (I'm using the word 'favourite' liberally here) onto it.
Netbooks typically do not come with any optical drive as they take up space, but this doesn't mean that we're going to be locked by our vendor's install OS.
While researching, I found that Windows 7 has a pretty decent tool, called the Windows 7 USB/DVD Download Tool, which helps you copy your Windows 7 ISO onto your flashdrive. I'm not going to paste the full instructions but here's a really comprehensive guide that should help.
At this point of time, Microsoft has pulled the tool off its website as it is under investigation for violating GPLv2 code, but nethertheless you can still grab it off another mirror here.