this small tutorial will illustrate how to have your usb working with virtualbox.  virtualbox has the usb support disable by default.  if you want to have your usb to work properly with virtualbox you would have to perform the following steps.

this tutorial applies for ubuntu 8.10.  but it might work with other distros.

steps:

1. type “sudo gedit /etc/init.d/mountdevsubfs.sh“
2. go to the following block
   #
# Magic to make /proc/bus/usb work
#
#mkdir -p /dev/bus/usb/.usbfs
#domount usbfs “” /dev/bus/usb/.usbfs -obusmode=0700,devmode=0600,listmode=0644
#ln -s .usbfs/devices /dev/bus/usb/devices
#mount --rbind /dev/bus/usb /proc/bus/usb

   change it to
   #
# Magic to make /proc/bus/usb work
#
mkdir -p /dev/bus/usb/.usbfs
domount usbfs “” /dev/bus/usb/.usbfs -obusmode=0700,devmode=0600,listmode=0644
ln -s .usbfs/devices /dev/bus/usb/devices
mount --rbind /dev/bus/usb /proc/bus/usb

3. now go type “sudo gedit /etc/fstab”
4. copy and paste the following code to your fstab
   none /proc/bus/usb usbfs devgid=1000,devmode=664 0 0

you are almost done.  now reboot your computer and you should be good to go.