Using a different SIM card on iPad2 3g while travelling outside the US? I have an iPad2 3g with at&amp;t. 

Now, Will I be able to pop another SIM into it when I travel outside the US and use the data plan available in that country/service provider??
Is the iPad2 locked to AT&amp;T's network just like the iPhone?
It's not locked and will work on any compatible network.