Google Plus has supported posting messages and receiving updates through SMS for a long time now.
This feature was however available only in USA and India at launch.
Google has now expanded the availability to 41 new markets today:
Afghanistan, Algeria, Angola, Bahrain, Benin, Cambodia, Cameroon, Congo (DRC), Cote D’Ivoire, Egypt, Ghana, Guinea, Indonesia, Iraq, Israel, Jordan, Kazakhstan, Kenya, Kuwait, Kyrgyzstan, Liberia, Malawi, Malaysia, Maldives, Morocco, Mozambique, Niger, Nigeria, Pakistan, Philippines, Saudi Arabia, Senegal, Sierra Leone, Sri Lanka, Tanzania, Thailand, Tunisia, Uganda, Uzbekistan, Vietnam and Zambia.
You need to enable this feature on your Google Plus account from here.