If you've got a Massachusetts address, you can get a Boston Public Library (BPL) eCard.
Register here. Be sure to fill out every field with an asterisk (*), enter a four-digit PIN of your choosing, and check the box saying you're not a robot.
Once you click Submit, you will get a confirmation email from the BPL. Follow the instructions in that email. Once you do, the BPL will send you another email with your eCard number. Save this email, and save this number somewhere! You will need to have this number, as well as the PIN you chose, to log in to the resources offered by the BPL's website.
Log in from the link in that email to complete your registration, and explore everything digital the BPL has to offer!