In AA we call it "being of service". We sponsor (e.g. mentor) other individuals, take commitments to help with the various parts of meetings (from making coffee to clean up to being the secretary of a meeting). There is also what is called H&I - which is hospitals and institutions, where we basically run a meeting at a hospital, jail, or treatment center.
Even if AA isn't your thing, you can help other alcoholics by sharing your experience, strength, and hope with them.
And like others have said, there are a lot of ways to help people who aren't alcoholics. Google "volunteer opportunities" with your city name, ask your local priest/rabbi/minister for advice, or just call up one of the large charities such as the Red Cross and ask them what you can do.
If you don't have a volunteer opportunities nearby, SR is a great place to help out too.
The key is to DO rather than THINK. Thinking always got me in trouble.