Yes, just call Verizon Global Support at 800-711-8300 and tell them you want to unlock your device for international use. I believe you must be a Verizon customer for at least 60 days and be in good standing.
To complete the unlock, you will need wifi access or be connected to iTunes when you insert the foreign sim (the iPhone does not use unlock codes like other devices). I would recommend purchasing an empty European sim on ebay for a few dollars to verify the unlock before traveling to Europe. You only need wifi/iTunes for the initial unlock, after that you can just pop in any foreign sim.