Using SendGrid's Parse API to Email yourself a Trello card
Nutshell: I used a free SendGrid developer account, a free Trello account, and a free Google App Engine account. I added a subdomain to iandouglas.com, set its MX record to point to mx.sendgrid.net, then modified a portion of py-trello to be appengine-compatible, and wrote some other Python code to answer a POST operation as a webhook. SendGrid would perform a POST operation to my webhook when receiving Email to any recipient at @mynewsubdomain.