Hi some one gave me a Psvita with AT&T 3G, I´d like to know how can I use it with a diferent operator / Hola alguien me regaló un PSvita con 3G de AT&T pero quiero usar otro operador como puedo hacerlo ?
You could try sticking a Sim card from a T-Mobile device into it, but it probably won't work.
It's a GSM/HSPA device and as such, only compatible with GSM/HSPA carriers. As imupindis points out, it's likely locked to ATT.
There is a zero percent chance it would work with Verizon, since they are a CDMA carrier.