Necessity truly is the mother of invention. With the political unrest in Egypt leading the government to shut down web traffic (especially Facebook, Twitter, etc.) in the country, protestors are turning to alternative means to get messages into and out of the country.
For a while, good old-fashioned dial-up access was the only way outside of courier pigeon, as phone service was spotty. Some ISP’s are offering this access, and even a French company is getting in on the action, although reports are indicating this might be shut down soon. So the enterprising souls at Google have taken the next step and launched a service that allows people to dial a phone number and leave a voicemail, which will be translated into a Twitter message.