[Alexander Lash] gave a short overview of what you need to unlock a CDMA phone. He strongly recommended Howard Forums for finding most of the info you need. You’ll probably need BitPim and the Qualcomm PST (product support tools). Using the PST you can flash your new carrier’s firmware and then activate the phone on their network.
Verizon offers two ways to get unlimited EVDO data. $59 for a data plan or $15 for VCast. You’re not supposed to be able to use your VCast phone as an EVDO modem and it sends a different network access identifier (NAI) if you tether the phone. Using the PST you can change the NAI and use the cheaper VCast plan for data access. Here is a forum post detailing the process.