At 02:55a -0700 01/16/2006, Chuck Pelto didst inscribe upon an 
electronic papyrus:

>Okay....
>
>....how do I determine the size of the disk image I need to create?

You can use 'du' to see the disk usage of your source folder. I would 
add some margin of safety to account for file system overhead (better 
safe than sorry).

Use the -k option to get it in kilobytes. Uh, I don't recall if 
that's in 1000s or 1024s.