Thoughts on text free user interface design

Earlier this month I stumbled upon the great work that the people at Microsoft Research are doing regarding technology applications for the emerging markets; in particular, I was interested in their work last year on text-free User Interface Design for the illiterate (which was so innovative that it was featured at the Metropolitan Museum of Art's Elastic Mind exhibit).

Then this morning on the bus to work I read an article about how people interpret expressions on faces differently based on where they are from: apparently people in East Asia are more likely to read the eyes of the face, while people in the West scan the whole face with an emphasis on the mouth. One example of how this difference is reflected in practice is the use of emoticons:

Emotion    West    East
'Happy'      :-)       (^_^)
'Sad'         :-(        (;_;) or (T_T)
'Surprise'   :-o       (o.o)

I am thinking about the challenges of bringing this text-free User Interface (UI) for the illiterate since it can't necessarily be mass produced because of cultural sensitivity to image interpretation. In fact, Microsoft Research arrived at their text-free UI after an "extensive ethnographic study."

Are there alternative approaches to extensive studies for creating text-free UI designs to rural environments? On the other hand, would the studies cover a large enough population to justify the costs? Would love your thoughts.