Nice.  I was integrating this, when I saw this:
"API Keys provide full access to your MailChimp account, so always keep them secure."
http://kb.mailchimp.com/article/where-can-i-find-my-api-key

Given that we're passing things around in text, I would prefer NOT to include our API key.  The URL-based method only allows others to muck with our mailchimp settings.

I could set things up such that our Mailchimp API key is in a file (such as utils.mailchimp) that is not included in our zipfile for download, but it still would appear inside our public repository.

For now, I'll leave things as they are; let me know if you object.