Fixed. Sorry! I had a recent bout with spammers :/ You can add a gist anonymously if you don't like to expose yourself, but having that functionality is quite dangerous online, for obvious reasons. I don't like captchas, but I'll have to add them soon (for anonymous contributions) if this continues.

I was just reading about spambots filtering without captchas, maybe you'll find it interesting too: http://nedbatchelder.com/text/stopbots.html