Leopard user template

sudo mv /System/Library/User\ Template/English.lproj /System/Library/User\ Template/English.lproj.old

This will give you copy of the original called "English.lproj.old" in the same folder. Then you may copy your new template file by executing:

sudo cp -R /Users/new-user-short-name /System/Library/User\ Template/English.lproj

If you prefer to remove (delete) the original try the command without the /* at the end: sudo rm -r /System/Library/User\ Template/English.lproj