Unlocked iPhone 4 in SE Asia

I am planning a trip in late Oct to China, Myanmar, Vietnam, and the Philippines.. Can I buy a local SIMM Card for my iPhone in each country so I can call to make hotel reservations or for other things? Thanks...

I was listening to talk-back radio yesterday and the commentator said that when he was in China a few years back, he purchased a Sim card to use and was assured that it would work everywhere. Not so. It turns out that there are many regions, each with their own Sim network, and for example, if you buy one in Shanghai, it won't work in places like Guangzhou. You will need to buy extra cards for every new district.

So for China, the answer is yes. I believe that the same goes for Vietnam (ie. you can buy one without issue). Not sure about Myanmar or the Phillipines.

Another option to consider. You can also buy a cheap Nokia in Asia for around $20 - $25. For many countries just switch sim cards. Most regular US cell phones will not work in Asia.

If you unlock your Iphone will it void your warranty?

Maybe not being "connected" 24 hours a day is a blessing. In Asia it is easy to use cheap internet shops for emails. If you are bringing a laptop there are hotels that have free wifi in many places.

I don't have an Iphone, too expensive and most of the options are not necessary for me. But I do have two cheap Nokias. One for the US only and one for Asia. I use the same Asian purchased Nokia cell phone in Thailand, Cambodia and the Philippines. I do travel with a cheap netbook that I use a lot with free wifi in hotels.

Up to you.

I am going to China soon how about 3G?? does this work ok?

The iPhone 4 will work everywhere except maybe Japan where they have a funky system

I highly recommend buying local SIMs when you get there. They usually cost a buck or two.

When I landed in Thailand one company was handing them out free in the baggage area, keep your eyes open.

I've gotten SIMs in Vietnam, Laos, Thailand, Cambodia, and Indonesia. I know in China its easy. All no problems (tho all different costs). Just beware how it uses data. If you don't have it setup correctly it might suck all your credit trying to check email. Best to buy a few dollars of credit first until you understand how its working. Having data is amazing though, maps work, public transit is often in the maps.

Most of these countries now have cheap VOIP rates for calling home too, like a penny a minute. Try to find out about that too.

If your iphone 4 is not locked to any network,then you can use it with any GSM simcards .
If it is locked to any network(carrier),then you have to unlock the network lock to use it with other networks.You can unlock it by using Remote Unlock Service provided by online vendors.It is very easy and safe than other unlocking methods.
Visit SimpleUnlocking.com to get Remote Unlock Service by providing country and current network name.You can use your iPhone 4 with any GSM SIM card around the world after it is unlocked.

Thanks legendarydragon