Here are a few websites that families of TCKs can use:
American Grandparents Association – Bridge the distance with creatie ideas that connect you and your grandkids from miles away – and keep you close
Grandparenting from a Distance – A book of activities and ideas for grandparents
Long Distance Grandparenting – The Foundation for Grandparenting offers ideas for grandparenting from a distance.
A Letter to the Grandparents of My Third Culture Kids
by Rachel Pieh Jones