Lots of kids are computer literate. Grandparents must become computer literate too. Happily, the cost to buy a computer is significantly less than in the past. Faxes are useful. One grandmother we know gave all of her grandchildren fax machines so they could keep in touch on a daily basis.
Children can fax jokes, report cards, drawings etc. to their grandparents and vice versa.
She faxes her grandchildren a little note of encouragement several mornings a week. Telephone contact is important too. But make sure that you call your grandchild alone. Your grandchild wants to feel special, and individual. If you want to call someone else, or talk with everyone in the family make a special call.