I do not have Verizon, so I've never tried this personally, but you should be able to call Verizon at 800-711-8300 and request a SIM unlock code for your phone (explain to them you want to use a local, non-Verizon SIM). Your phone will require reconfiguration to use the correct data connection settings (APN, see the providers like I provided above), but you should be able to use your Droid once you arrive and purchase service.