We've just added site-wide token based authentication. You can find your API token in your account page, front and center.
token to any URL which requires authentication.
curl -F 'repository[name]=API_Hotness' -F 'login=defunkt' -F 'token=6ef8395fecf207165f1a82178ae1b984' http://github.com/repositories
We'll be enhancing the API soon, but in the meantime you can use this to more easily build tools and automation around GitHub. Enjoy.