Now a days USB storage devices are common in the industry. This is very halmful in any unsecured network. Because this devices are considered to be the virus spreading agents. In corporates USB media is prevented because of above said reasons. So here a small tip to prevent USB storage in Linux machines through GRUB.
Scenario
OS : Debian / Ubuntu
Open the Grub configuration file
#vi /boot/grub/menu.lst
Add "nousb" at the end of the Kernel Line. Like the following
kernel /vmlinuz-2.6.18-128.1.1.el5 ro root=LABEL=/ console=tty0 console=ttyS1,19200n8 nousb
Secure GRUB with a strong Password !!!
#/sbin/shutdown -r now
So nobody can use USB storage unless you allowed to do so.