I am just pasting a post here that describes my experiences over the last couple of years with respect to mobile options at a couple of foreign locations.1. Hong Kong - 2010 - didn't take matrix as I had HTC Hero cdma then. A friend brought a local sim from there called smile chat chat. Weird name but very economical. Calls to India were less than a rupee per minute.2. Spain - 2011 - got matrix. Expensive. They charged me 25 rupees per day for an incoming free sim. Outgoing calls were expensive. Bought another prepaid sim (happy movil) from there. Good cheap calls and data.3. Singapore - 2012 - decided not to take matrix. Bought a starhub prepaid sim for about 500 from the airport. Good talk time within this money and about 300 MB data. Cheap outgoing calls to India using idd. Had free wifi in the hotel too.4. Kuala Lumpur - 2013 - again gave up on matrix. Bought a Maxis hotlink prepaid aim for about 600. Again cheap outgoing calls using idd. 250mb data.5. China - 2013 - once again did not take matrix. Wanted to buy China Unicom prepaid sim. But did not get time and since wifi was free in the hotel did not buy. Using
Google voice credit to call phones in India (2 cents per minute) and whatsapp for im. Gtalk for video chat. Writing this message from China right now. I do not have a G voice number so I can not use my phone for it and have to use my
laptop.Unfortunately no twitter, Facebook and Wikipedia in China.
All in all I would say matrix isn't the best option and turns out to be pretty expensive if you want to make outgoing calls. Most of the times, you will get a cheap prepaid sim from airport or a 7/11 shop. In fact while on my way to Kl, a friend spotted a stall at the ig international airport that was selling prepaid sim cards for various countries. He bought one for kl (don't remember which provider) and it worked well there.Also free wifi comes handy to make voice / video calls.TripAdvisor is a good website where people discuss various prepaid sim options to in different countries.