Search by SMS never really took off, but by referring to a patent that was recently filed by Yahoo, the company seems like it wants to take a crack at the challenge. In the patent, it’s mentioned that users will be able to use the system by sending a search query as a text message to a predetermined number, after which the search query is processed, and the results delivered, along with some advertisements, to the user. The search-related advertising here might be rather interesting, especially if there is widespread adoption of this technology, it would present a nice revenue stream for Yahoo. Currently the technology is targeted at developing countries, where mobile phone penetration is high, but the Internet services are rather low. Sounds like a rather useful service, though it remains to be seen whether it would be well received and used if it were to be rolled out.