The Second Strings Project, started in 1999, is a campaign to collect and distribute used guitar strings to needy musicians throughout the world. This effort will help keep musical creativity alive in countries that might otherwise die.  Details about the project are online at secondstringsproject.org.
The website asks that guitar strings be donated as a set in the original packaging, so save those too. Local member Col Bernau is the point of contact and is looking into setting up collection boxes. Contact Col by email if you want to participate.