Straight Talk Sim Cards are now available. Originally all Straight Talk phones were CDMA which means they did not have SIM cards.
There are several options with Straight Talk SIM Cards.
Straight Talk Phones
One type of SIM will only work in Straight Talk phones. These cards will come with any GSM Straight Talk phone. They will only work in the phone they are activated in. You will not be able to use these SIM cards in an unlocked phone or transfer them to another Straight Talk Phone.
Unlocked Phone SIMS
Another type of Straight Talk SIM Card is the new Card that can be used in Unlocked GSM phones. These cards just became available in 2012 and can be used in nearly any Unlocked GSM phone. Your unlocked phone must operate in 850 and 1900 MHz bands.
Some functions of the phone and the Straight Talk service might not work properly with an Unlocked phone and a Straight Talk SIM. There can be little compatibility issues that crop up. Your voice and text options should work fine. Check out my experiences with Straight Talk Customer Service.
AT&T Phones For Straight Talk
At&t is a major supplier of StraightTalk Service. If you have an AT&T phone you can purchase a Straight Talk SIM card to use in this phone.
T-Mobile Phones for Straight Talk
T Mobile is a supplier of Straight Talk Wireless Service. If you have a T-Mobile GSM phone you can purchase a STRAIGHT TALK SIM card and use your current phone.
The At&t phones and the T-Mobile phones that you get a Straight Talk SIM Card for should work the best. I believe there will be more problems with most Unlocked phones and the Straight Talk Sims.
Straight Talk Customer Service
Also I do everything I can to avoid Straight Talk Customer Service. In my experience they cannot correct most problems you have and you will spend anywhere from 30 minutes to an hour trying to get your phone fixed.
For the easiest Straight Talk experience, I would buy a Straight Talk phone and not try to use one of their SIM cards in a phone I already had. I have had several unsuccessful attempts to solve problems with Straight Talk Customer Service.
I love the price of Straight Talk Phone service and use it. I avoid using Straight Talk Customer service.
The best deals are available on the web at Straight Talk Online . Straight Talk Prepaid Phone are also available at almost every Walmart in the US. Even so I have never seen a free Straight Talk Cellphone at Wally World. There are always free Straight Talk phones online.