Ipad internet use in other countries?

[marcegc31]

I have the new ipad 3 with the 4g.. It's the ATt&T one... My question is... Can i insert asim from any carrier in any country? For example if I travel to Colombia and purchase a plan over there for my iPad and insert the sim card from any company over there would it work just fine or do i have to unlock my ipad in order to do that?