I recently had the need to install an OS onto a netbook that doesn’t have a CD drive.  How does one get a bootable USB flash drive?  I have a laptop with a DVD drive so that I can take a CD and copy it to a USB flash drive, but just copying the contents won’t make it bootable so that you can install an OS. I spent a few days researching the subject and after numerous trials, I found two solutions worthy of mention.

For Linux ISOs, I found UNetbootin to be extremely easy to use and works quite well.   I would use this solution even if a CD drive was available since this means I would not have to burn a CD/DVD and could just (re)use one of the many flash drives I have lying around ($12, 4GB drives ftw).

For Windows, specifically WinXP although it also works with Vista and a few others, I highly recommend USB_MultiBoot_10.  It was the only series of programs that would reliably copy a CD onto a USB flash drive and make it bootable.  It was more complex than using UNetbootin, but I suppose that cannot be helped.  At least it worked!  This would even allow you to set up things for unattended installs which is very handy!