There are countries where citizens still do not have internet access and are therefore denied the basic access to knowledge that we all have. Some of these countries however do have basic access to email messaging. I wondered how difficult it would be to create an email auto-responder that retrieves a Wikipedia article based on the "subject" of a received email and replies to the email with the text from said Wikipedia page.
e.g. person in underprivileged country sends email with subject "Franz Liszt" autoresponder replies to email with the text from the wikipedia page:
Should be pretty easy to do. Periodically query users.history.list() for new updates to the mailbox and if it's a new message simply users.messages.get() it, look at subject, get the wikipedia content, and then create an RFC822 email message (full headers + body in one string), url-safe base64 encode it and post that to users.messages.send() to send the reply!
More details on each of the methods can be found at: https://developers.google.com/gmail/api/
If you have specific questions about one of these three calls or something else update your question to be more specific.