Combine learning with service in a variety of ways. Most large charities or political causes have an on-line presence. Many include teaching activities. Students can tutor other students via email. Messages can be sent to shut-ins.
Students can petition for causes they support.
Paperless activities support recycling. Many organizations post lists of activities that are appropriate ways to provide support. Do you want a non-disruptive way to send birthday greetings. The Internet has all of these things and more for any kind of special day in the classroom.