One of the technical challenges that our team faces is to parse the SMS messages once the server receives them. At MIT, there are several EECS professors working on natural language processing. Below are two CSAIL professors who also distribute source code (free parser download).
In our project deploying country, people may speak and write in other languages than English. It might be a complex task to interface a natural language parser depending on the parsing algorithms used. An alternative for prototyping is to use a "coding book" for SMS messages encode/decode; this requires user education of the "coding book".