You can login as a Flipnote creator even if you don't have a Hatena ID.
You can login if you have a Nintendo DSi, and won't need to use an email address or Hatena ID. You can also watch Flipnotes specially optimized for you.
How to locate your secret code
You need to know your secret code to use Command Login. You can find your secret code in your Creator's Room on Flipnote Hatena for Nintendo DSi. (If you have a Hatena ID, please login with your ID and password)