Hi Jeff,

>> 2. How can I unmount the external Backup drive when the script is  
>> done, so it can be safely unpugged (FireWire)?

> /usr/sbin/diskutil eject '/Volumes/The DriveName'

That seems to work great, thanks :-)

Now I just need an answer to:

>> 1. How can I check whether the external volume "Backup" is  
>> mounted, and conditionally execute the script (else mail to say  
>> there was an error). Simply checking whether /Volumes/Backup  
>> exists isn't reliable since there may be a directory created there  
>> (as I've seen created when the script runs with no disk attached).

Thanks,
Tom