Give Your Presence, Or Calling Cards
With Mother's Day and Father's Day coming up, the best gift you could ever give is your presence. But if this is not possible, send them several prepaid calling cards so they can keep in touch with you and their grandchildren more often than maybe their budget will allow.
And since the printing on some of these cards can be pretty small, copy the numbers they are to use onto a seperate piece of paper so they can use your gift more easily.
Add your voice to the conversation.