Sometimes I want to reply to a comment on my anonymous memes, but I can't without making it obvious that I made the meme. There could be an anonymous check box for an anonymous creator to reply with. You could also leave a reply attached to your user name if you want.
I like the idea... but honestly it seems like if you can't give your fake username away to a meme, then you shouldn't really be posting the meme, or at the very least don't need to reply... maybe I just don't get it.