A useful module, but its origins as a feed management tool show through too much. The documentation refers to the content that is fetched as "feed" sometimes, even when it doesn't need to a feed at at all.
It's currently not an attractive tool to mirror image files (or other sizable files with), because it would put the whole file into a Perl data structure and serialize it and cache it that way. Something like mirror() from LWP::UserAgent may be more interesting in that case.
Still, it has some neat features like Gzip support and comprehension of cache-related HTTP headers, and may be worth a look for inspiration, even if it doesn't exactly match your needs.