Apple World Travel Adapter Kit - Apple Store (U.S.)
This is the world adapter kit that should work with the iPad adapter. However it is very pricey and it does include the iPod/iPhone adapter so you are paying for one you can't use with your iPad.
I traveled with my iPhone 2G last year and I refused to pay for something so expensive and limited. The 2G power adapter has the same form factor as the iPad adapter.
What you are looking for in the fine print on the adapter (and I've confirmed this is on the iPad adapter) is:
Input 100 - 240 Volts, 50-60 Hz That means it is international. You can safely use it just about anywhere in the world.
Every iPhone or iPad adapter that I've had my hands on has this, but get out your magnifying glass and read the fine print to make sure.
This is where I buy most of my plug adapters:
Adaptor & Converter Kits | Magellan's Travel Supplies
You only need a plug adapter, not a power converter. There are many other sources, too. Google is your friend in the hunt for plug adapters. The beauty of a simple plug adapter is that you can use it with other gear. In my family, we just pass the adapters we buy on to the next person going overseas. (generally someone is going somewhere every year or so -- if you are a frequent traveler, just keep it for the next trip).
Here is a good site with more information about electricity around the world:
Electricity Around the World
If you want to make sure, you can also inquire at the hotels/residences where you will be staying. Then you will make sure you are buying and packing the right adapters. For the iPad, you don't need a grounded adapter, but they can be used, so I generally get a couple of grounded and a couple of non-grounded to handle all my gear. You can also buy powerstrips (I got a France/Germany one at Amazon for $14 last year) if you need to plug in a lot of gear. I just make sure I have a dual voltage hairdryer, and the right kind of power adapters for my electronics. Then all I need are the plug adapters.
P.S. The spellings "adapter" or "adaptor" are both technically correct, however "adaptor" is not used as often.