You'll now find this site has a 'Sign up' box on the homepage — add your email, hit enter (that 'return' key) or click 'away' from the input field. I sprinkled some Javascript magic on that, and it'll hand over your email via XHR (simply, AJAX), to a background job on Redis via Resque.
The background job, fires off that email over to Mailchimp. How's that for amazeballs?