Have you ever heard of "Mail Art"? Wikipedia defines it as a populistic movement centered on sending small scale works through the postal service. My brother used to send me letters in the mail where he created the envelope out of whatever paper he had lying around. He would turn the envelope into a piece of art. Some common elements of Mail Art according to Wikipedia, collage, recycled images and objects, artistic created stamps, paint and include anything that can be put into an envelope. I think of mail art as tactile and beautiful. I think the way the postmark is randomly placed adds an uncontrolled element to the art work.
Next time you want to send an email to a friend or relative, take a little more time and send them some mail art. Create the "art" using items you have around the house or office. I think you will be surprised by what you can create and the letter will be treasured by its receiver.