Thousand thanks to Martin Winkler for making an ultra-useful captcha app for django here. It’s super-easy to use although if you want to use it with Django 1.1 you need to modify it first.
I made the patch for Django 1.1 compatibility, which can be downloaded here.
I also made some other patches to remove md5 deprecation warning (here) and to fix a font-loading bug if you use the app with Subversion/git/some other VCS (here).
UPDATE: It seems that Martin’s site does no longer exist, so I put the Martin’s originals along with all my patches on github.
