If you're reading this, you definitely have something to offer. It doesn't matter if you're young or old, if you have a skill you can share, I promise there'll be a teacher who wants to learn. Phone up the central administration of your local school district. They should be able to put you in contact with the appropriate teacher or technology coordinator. These individuals can in turn do some polling to see who's interested and what curriculum objectives or projects are primed for technology integration.
People have the highest motivation and learn most effectively when they have a goal.
Public libraries, churches, youth programs, home-schooling groups are some other avenues to explore. If you use the Internet, be an e-mail partner with a teacher or a group of teachers. One very simple thing I did with my daughter's Kindergarten teacher was to surf for Web sites that were very visual and didn't require a lot of reading skills to enjoy. Teachers don't often have time to surf the Web. Offer to teach a staff development course.