You used to have to add yourself to the plugdev users group and unmount
the USB device in Ubuntu and specifically mount the device in the VM and
jump through all sorts of other hoops to get USB working with VB.

Now, it's quite a bit easier. You install the USB extension, go into
the VM's settings, add each device you want the VM to be able to see
under the USB tab and go.

At least, that's all I did and I have all sorts of USB devices (although
not, I have to say, an iPod or iPhone, because I don't have either)
working very nicely in my XP VM.