After talking to Net10/StraightTalk/TracPhone (All the same company under AT&T) for about 4 hours total in the past 2 weeks I can guarantee that you cannot use another sim card on a same-brand phone, let alone use the sim card from these phones on another phone.
Why? Each SIM card is bound to their device. So once it's registered to that device, it's locked there. I highly doubt Net10 will allow anyone to jailbreak/unlock their devices for other carriers.
Trust me fully when I say this : This set of companies? Care about you less than they care about the money. I've been stuck with them for three weeks so far trying to get my number out from them and so far it's been one thing after another. Having me BUY another phone, just so I can use my number on another carrier which I had ported in from Verizon to Net10.
I'll be watching this regardless as I'm interested in the Android devices in general to mess around with, but as a phone company, you're better off elsewhere. :\
Flag if you want, hide this if you want. Just know that I warned users here.