Just buy it when you're there. I bought one in NY before going to Europe a few weeks ago, and the adapter didn't work in any countries except Greece.
Also, make sure your electronics support 220v. You still need the adapter, but if your appliance doesn't sport a range that include the voltage of the country you're in (110- 220 or 110 - 240 are common ranges), then you'll also need something to transform the voltage, which is heavier and more expensive.