Not really. You could probably use the ISO to turn the USB drive into an install disk but you can’t boot from it if you do that, all you could do with that is install vista on your computer as far as *actually* installing vista on the USB drive goes you can’t do it unless you have an extremely large USB drive of a size which would still at this point in time be prohibitively expensive for most people, and I really wouldn’t recommend doing it with a USB drive with less than 128 GB of storage capacity.
Not really. You could probably use the ISO to turn the USB drive into an install disk but you can’t boot from it if you do that, all you could do with that is install vista on your computer as far as *actually* installing vista on the USB drive goes you can’t do it unless you have an extremely large USB drive of a size which would still at this point in time be prohibitively expensive for most people, and I really wouldn’t recommend doing it with a USB drive with less than 128 GB of storage capacity.