filenames starting with a '-'

I was using gphoto to get some images form a camera and didn't assign a
default filename to prefix the -001 -002 -003... etc.. Now I've got a
bunch of filenames that start with a '-' and when I use cp or mv on the
files it thinks that it's an option instead of a file. Is there an
undocumented option that will make cp/mv realize that it's dealing with a
file? There are other ways to solve the problem but I'd like to know how
to do it with cp/mv...

Don