An option to mount several images as one would be great. One would need a virtual filesystem that accesses several discs instead of just one.

One problem would be the potential for file overlap, which could be solved by an order of precedence: the first disc listed has first priority, the second disc listed has second priority, etc...

This would help multi-disc installs run smoothly. Also, it would help cd2dvd conversions. (In fact, it would probably have to work by some sort of virtual cd2dvd conversion.)