I am sure many of us travel abroad for short trips. Even if we have to get roaming on our mobiles (the changes are CRAZY we may still wish to have local mobiles:
In the US getting a SIM/CDMA connection takes ages, so kids take a SIM from India.
In the Gulf the shortest duration of a prepaid is One Year, so for a short trip taking a SIM from here makes sense. In the Gulf (at least Dubai) data charges can be crazy. Matrix advised me that GPRS may be as much as $10/MB! Also, most hotels charge AED40 per hour (120 per day) for wireless connectivity. Some malls, and airport do have free connectivity.
I took a Matrix SIM at Rs.500 (or rather 550 with taxes) with a 10 day validity and 500MB talk/sms time. The SIM was on du and worked instantly. Of course make sure you switch off all data services before landing else you inadvertently get fleeced.
I will like others to post about alternate channels, experiences.