There are 2 versions of the HTC Hero, one is GSM (compatible w/ At&t/T-mobile) and one is CDMA (compativle w/ Sprint/Verizon). As long as you are using T-mobile or At&t you can unlock it to be compatible, but unless it is branded as a Verizon handset you cannot activate it on the Verizon network even if it is CDMA. No unlocking of the phone will change that. Make sure you know which version of the phone you are looking at.