Currently their is only the extra repository from Notch Interactive available on Github. Feel free to send an email to chuck@notch-interactive.com if you want to add your Chuck module repository to this list.
To add another module repository you have to download it to a local folder and define the module_basedirs variable in your config file ~/.django_chuck.conf.
module_basedirs="/some/dir/to/additionial-modules","."