This is the command to print the UUID for a device. This may be used with UUID= in /etc/fstab as a more robust way to name devices that works even if disks are added and removed. Ubuntu 10.04 uses this in their /etc/fstab file.
Print UUID to partition /dev/sda1
# blkid -o value -s UUID /dev/sda1
Print all UUIDs on your system
# blkid -o value -s UUID