The announcement was made on Google's official blog:
Like many people we've been glued to the news unfolding in Egypt and thinking of what we could do to help people on the ground. Over the weekend we came up with the idea of a speak-to-tweet service--the ability for anyone to tweet using just a voice connection.
We worked with a small team of engineers from Twitter, Google and SayNow, a company we acquired last week, to make this idea a reality. It's already live and anyone can tweet by simply leaving a voicemail on one of these international phone numbers (+16504194196 or +390662207294 or +97316199855) and the service will instantly tweet the message using the hashtag #egypt. No Internet connection is required. People can listen to the messages by dialing the same phone numbers or going to twitter.com/speak2tweet. We hope that this will go some way to helping people in Egypt stay connected at this very difficult time. Our thoughts are with everyone there.
The blog was co-authored by Ujjwal Singh, the co-founder of SayNow and AbdelKarim Mardini, a Google product manager in the Middle East and North Africa.