A few weeks ago my grandma asked me about
Twitter (for whatever it's worth) and over the last few months both my parents have gotten accounts. In thinking about this, it's kind of a perfect platform for parents looking to keep up with their adult children. I realized in a conversation this morning that the answer to the common Twitter question, "who cares what I ate for breakfast?" is your mom. She wants to know that you stubbed your toe, ate a hamburger and went back and forth to Atlanta yesterday (the last actually happened). It's exactly this sort of information that keeps you close to your loved ones (though obviously more detail would be nice, but that can always be provided in your other interactions).
Anyway, just thinking out loud.