I would ask whoever is hosting you in Hungary what the best provider is or wait until you get there to see what is available. I went to the UK, Germany and Switzerland in April and purchased prepaid sims (no contract) in 2 out of the 3 countries I visited for about $10-20 USD each. You will probably have to get a new SIM for each country you visit or pay for roaming, but depends on the provider. When you get back to the US, just put your Verizon sim back in. Unless you suspend service, you'll still have to pay for your regular Verizon service while you're abroad.