"The Fortune At The Bottom Of The Pyramid" is excellent too: http://www.amazon.com/Fortune-Bottom-Pyramid-Eradicating-Pub...

Excellent point about tech products for emerging markets. This is absolutely true. I just want to point out that people normally think that "emerging markets" are the same as "developing nations", when in reality it means "underserved markets" (aka "bottom of the pyramid"):

In developing countries, the middle-class or above has access to the (more or less) same life style as in developed countries, and thus products can be launched without much modification -- Localization is normally enough. In the other hand, undeserved markets do have its own set of challenges, which we technologists are normally unaware because most of us never experienced life in those conditions.

Also note that developed nations have underserved markets too: For example, if you are in Bay Area, just drive around East Palo Alto or East San Jose and note the diversity and number of products developed specifically for those communities.

Here are a few excellent resources on the subject of underserved markets

http://www.amazon.com/Fortune-Bottom-Pyramid-Eradicating-Paperback/dp/0131877291/

http://www.nextbillion.net/

http://rdvp.org/

http://www.nokia.com/A4126014