I'm trying to figure that out too.
My webplayer is being shipped, and I have been trying to read the famewolf image file off of the copy I've got on my desktop.
My limited understanding is that the IMG file is a single file compliation of everything that is in a HD partition. I think that it is similar to the type of files that would be used by certain backup programs, or disk imaging programs such as ghost.
If it is true that it is like a backup image of a hard-drive partition, then what program lets me look inside of it?
For your first question, second. I'm looking for the answer at this link