Not quite. Straight Talk operates on either T-Mobile or AT&T's towers depending on what SIM you buy. Both types work in unlocked phones, of course, but the AT&T network ones will work in AT&T locked phones. Same deal for T-Mobile network SIMs.

However, if you have an iPhone, it will detect the Straight Talk AT&T SIM as an AT&T SIM and remove your access to change APN settings. This is what happens when you have an iPhone with contract AT&T service. Straight Talk has different settings. So, when you walk out of the store, only calls will work. Data and MMS will not. To get those working you can go to http://www.unlockit.co.nz from your iPhone when you get on WiFi. They'll push the settings to you.

If you get the T-Mobile Straight Talk SIM, you will have access to change the APN settings on the device. However, you won't have the same coverage and 3G speeds will only be in areas where HSPA+ was refarmed to the 1900MHz band. Of course, your iPhone must be unlocked.


Yes


Some Walmarts are stocking SIMs. Both regular size and micro are available in the AT&T flavor. I believe the T-Mobile ones are only regular size at this time.

If your Walmart isn't stocking SIMs, you can go to Best Buy and pick up a NET10 SIM. It's the same deal and same parent company that runs Straight Talk. The monthly rate is $50 rather than $45.