Acer's Aspire One netbook laptop comes without an optical drive. It does comes with a DVD, though, that lets you either install Linpus Linux OS to the netbook by connecting an external USB optical drive to it, or create a recovery USB drive using the DVD in other computer (a Mac, in this case).
In order to use the DVD, you are supposed to boot from it, but Macs will not recognize it as bootable media.
I used VMWare Fusion to create an "Other Linux 2.6.x kernel" virtual machine, inserted the DVD, and the VM automatically booted from the DVD without having to leave my Mac OS X environment.
The wizard that comes up does not recognize the SATA drive in my Macbook (understandably, since the Acer Aspire One comes with no HDD). It will consider, conversely, the first USB flash drive it finds to be the local HDD, and any subsequent USB flash drives to be just that: external USB flash drives.
So, if you want to be able to create a recovery drive using an external USB flash drive, you need to have two flash drives connected to your Mac, or else it will not list any as an option.
[kirkmc adds: This is one of those hints that, while not directly Mac-related, may help someone out there. Needless to say, I haven't tested this one. I've got a MacBook Air, and I can use Remote Disc if I need to reinstall the OS.]
Mac OS X Hints