* if imagefile is damaged, ask user to zero the problem place, keep old blocks,
     overwrite with damaged blocks.
  in all cases, filesystem will have to be checked.

* do same thing if harddrive is damaged

* outputs on CD-R/CD-RW
* outputs on tape 
* outputs on zip device with auto mount/umount
* dump partition over other partition without creating imagefile
 
* support multicast
* supprt IPv6

* add filesystems 
  BSD FFS
  IBM JFS
  SGI XFS
  Solaris UFS/sunx86
  
* support for TLS

* support capabilities (at least under Linux) to improve security