From my research on the net it looks like the phone is CDMA technology and can only be used with Sprint.
That makes it useless.
I switched to T-mobile from AT&T (using my unlocked Iphone) on a month-to-month plan which cost $49.00 a month for 750 minutes and has both our phones running with no additional price. I can add a limited data plan for less than $15.00 a month. No contract, 2 phones, data and a phone that can be used worldwide. You can't beat that. From what I understand the EVO isn't GSM (no SIM card) but CDMA and can only be used with Sprint.
Useless.
If I'm wrong, someone fill me in.