This Stanford Social Innovation Review reports on SOFOLES --a Mexican microlending program (read more about it in a 2000 Harvard report) that has succeeded in making home ownership more affordable for low-income residents.

It's not the newest idea, but the report has interesting sidenotes; referencing the impact of money sent from migrant workers to their families in Mexico (these remittances are famously influential, both economically and politically), they mention that Margarita Quihuis has a start-up idea for a debit card company called Indigo Financeras, that would allow migrants to deposit directly to Mexican ATMs.