At the moment all you can do is host the file somewhere else on the web and link to it on this site. File uploads have been (understandably) disabled to save on web space.

As for pictures, well, I think that's being looked into at the moment. Again, you won't be able to host the pictures directly on the BBS but you will be able to link to them so that they appear in your posts. It's a case of "Watch this space" I'm afraid.