Using dd to clone disk

Hi, I bought a new 160gb sata disk to backup my 2008 macbook one of the same size. It's easiest for me to connect them together using linux and use 'dd' command
but havent figured out how to get the new disk to boot. Running the disk util from the 10.5.6 OSX disk, i repaired the disk and permissions, then
bless --folder "/Volumes/Mac.../System/Library/CoreServices" --bootinfo --bootefi
but it still just gives the busy crusor at boot time. Any ideas ? Cheers.

Use real cloning software that can render the clone bootable: Carbon Copy Cloner: LINK

Although I always like to support the use of Unix tools, you may be making this more difficult than it needs to be. As chscag recommended, use one of the free cloning tools like Carbon Copy Cloner or SuperDuper.