dd for disk duplication

I got to use a couple of my favorite utilities yesterday.  The first is the system rescue cd.  They finally updated the buger a couple of months ago.  It is now just about the best rescue cd in existance.  The second utility is dd.  I combined these two utilites to make a copy of the original laptop hard drive to one that I had connected via usb.  dd if=/dev/hda of=/dev/sda .  The copy took a while, but my system booted without issues on the new hard drive.  Sweet.