If a viable opportunity for making small loans existed, then I would expect local financial institutions to fill that need. When those institutions do not exist, there is usually a reason, such as the lack of an adequate legal and financial system for recovering debts. Without the ability to enforce payment obligations, the line between lending and charity becomes rather slim.
It's also unrealistic to expect most people receiving micro-loans to operate effective businesses, given their limited educations and lack of direct exposure to Western entrepreneurial values. Perhaps their living conditions could be improved more efficiently by a non-profit that gave away the right to operate franchise businesses using a proven model?
I don't have the expertise to know what kind of business would be optimal for people with limited resources. But when I see the success of immigrant-run franchises within the United States, I can't help but imagine that the underlying principle could be harnessed to generate wealth for needy people overseas.