Yep, Indonesian is another citizenship;
Was young Obama Indonesian citizen?
Document, travel suggest ‘Barry Soetero’ member of world’s largest Muslim country
http://www.wnd.com/index.php?pageId=72656
Obama’s American mother, Ann Dunham, separated from her first husband, Barack Obama Sr., in 1963 when the presidential candidate was two years old. Dunham and Obama Sr. are reported to have later divorced. Dunham married Lolo Soetoro, an Indonesian, and moved to Indonesia sometime between 1966 and 1967.
It was not clear whether Soetoro adopted Obama, either in Hawaii or in Indonesia, but there is strong circumstantial evidence that he did as far as Indonesian law was concerned.
In Indonesia, which was under tight rule in 1967, Obama clearly took on the last name of his stepfather in school registration documents. All Indonesian students were required to carry government identity cards, or Karty Tanda Pendudaks, which needed to bear the student’s legal name, which should be matched in public school registration filings.
Following his enrollment at the private Assisi school, Obama attended public schooling in Indonesia until he returned to Hawaii at age 10. According to Indonesian legal experts, it was difficult to enroll non-Indonesian citizens in public schooling.
Obama arrived in Indonesia at about the age of five according to most accounts, although it was possible he arrived at the age of six, according to a few sources. If Lolo Soetoro adopted Obama at age five or younger, then Obama would automatically have become an Indonesian citizen according to the country’s laws in the 1960’s, which stipulated any child aged five or younger adopted by an Indonesian father is immediately granted Indonesian citizenship upon completion of the adoption process.
Lolo Soetoro could have adopted Obama in Hawaii, although such an adoption would not have necessarily been recognized by Indonesia.
Indonesian law at the time also did not recognize dual citizenship, meaning if Obama became Indonesian, then as far as that country was concerned, his U.S. citizenship was no longer recognized by Indonesia. But U.S. law would still recognize Obama as an American citizen.