[Cooker] ISO images - is a binary diff file possible ??

[stephen]

Having only just finished downloading Beta3, the air became
slightly colourful when as browsing email I saw RC1 mentioned,
closely followed by a 'here we go again' feeling, my computer 
is definitely moving out of my bedroom.

I should perhaps mention my modem, that's why I waited for
a slightly longer lasting beta than 1 & 2 ;-)

Questions:: 
1. Would a binary difference file be possible ?
2. Would it necessaryily be significantly smaller ?
2a. How would it compress ?
3. If it was say 20-50%, would you produce one for the mirrors ?
4. Would it be similar for 'Extension' cdroms ?


Stephen R Parkinson.