theoretically, yes. realistically, probably not. cdma phones are a lot trickier to switch between networks than gsm phones. see with a gsm phone, the programming information is contained on the sim cards. your sim id is already programmed into the carrier's system and you just pop that sim in an unlocked phone and bam, you're in business. with cdma phones, the programming information is all within the phone iteself. since the evo didn't come from verizon, they don't have the msid programmed in their system. while it's possible to get this entered, it's hard to find someone competent enough to do it. so if you can find someone willing to put in the effort to get it working, yes, it is possible, but good luck finding someone with the access and knowledge to get this done. most likely they'll just tell you it's not possible.
holy wall of text.