Why do you need to use USB? Is it because one of the computers has no ethernet port? If so, a USB ethernet adaptor would seem the simplest solution, not only for this task but for doing anything network related.
It would also be cheaper than one of those USB datalink cables, you can't use a normal USB cable because both computers have USB host ports, which you cannot safely connect directly.
"Insanity: doing the same thing over and over again and expecting different results." (Albert Einstein)