Some easy way to capture a written reply would be good too. Voice is personal; email not as much. Handwriting is personal for me. Maybe it's a smart phone app that makes it simple to take a picture of a letter or note card. Maybe it makes sense to suggest replying on a 3x5 card or something (instead of a a full sheet of paper) and maybe that simplifies the photo issue. The digital record is captured and then a physical one can be kept. It can also be extended to have your parents take a picture of a picture of their favorite memory