The kitten (asirra) captcha was cute, but for some reason stopped working a few weeks ago, preventing new users from creating wiki accounts. It's too bad because Asirra was working rather well to prevent spam. We have reverted to reCaptcha, which is certainly worse, with 3 new spam user accounts since the change was made 24 hours ago.
Does anyone have some experience with mediawiki and can point us in the right direction for tightening things up?