Di, I am not my uterus. The world is not divided into grandmothers and other people. We all have skills and good intentions: those are all that's needed to help others.
I have an idea: I'd like to see something about helping older women seek their place as connectors and mentors. All too often I think we're overlooked as no longer cool and young, but we can do all the things mentioned in this thread and more. Helping to set up a community clearing house to match people with needs might be a great way to help some folks step out.
More: staying up-to-date with electronic media. These are just tools that can be used to do research, connect people, disseminate information.
Taking care of our health. If we learn good habits, we can set an example for everyone around us and still keep moving.
Dotsie had a great idea for relating to your adult children, but it could be expanded to include women our age and our relations to everyone else. We're all going through stages in life and adjusting to them can have a huge effect on our relationships to everyone else.