Geniice told me on IRC, if I understand correctly,
that you might change a copyrighted image (fair use or not) if it is a very
small part of the original, like for a parody (under USA-law). But album
covers are not part of this.
Not quite. Those were the first examples I could come up with. It is
not say there are not others but since en.wikipedia does not allow
modification of fair use images it isn't a subject I worry about very