I've got a article (with VB.Net source code examples) on how to get the serial number from a USB flash disk.... you might find it interesting as it shows how to enumerate the USB controllers, hubs, ports, and devices.
http://www.emmet-gray.com/Articles/USB_SerialNumbers.htm
There is a related C# source code example (at the bottom of that link) for a USB_View utility that performs the same kinds of things as a class module that you could compile separately and use in your VB project.
