Let's understand what it takes for a successful trip: you want it to be adventurous yet, not inconvenient! (find it on twitter #3traveltips)
Today will talk about international travelers' tips: your phone service, international roaming services and your unit!
Find our from your company if the sim car in your phone is internationally ready for the overseas service.
Determine early enough before your departure, when the service starts and ends, clarify rates in each country, have the company send you an email or something in writing about the contract.
Don't buy a new phone right before you leave for your trip; this implicates a lot of stress; having to set up the unit and know that it's all in best working order, all your data is sync-ed; you might be better off with a unit you are familiar with.
Eliminate any issue that you have that takes to much time to spend with before your departure!
Plan wisely. Go joyfully. Relax.