Recent years have seen a new means of helping third-world populations better their living standards: micro lending, of the type done at Kiva. This is an easy and practical way to make a positive difference in the lives of people living in the world's poorer regions.
Basically, you open an account with the organization, and then peruse their list of applicants and select those to whom you would like to lend. These are generally people who have small businesses and are looking to expand or upgrade equipment. The amounts needed are small by our standards, but allow the applicants to improve their situations.
You make loans of as little as $25, and as the applicant repays the money (there is no interest), you can lend your balance out to others. The beauty of this process is that you can take a couple of hundred dollars and use it over and over to help out many people. Highly recommended.