I'm from a visa waiver country, and planned a trip to the U.S. last year to visit family. However, the immigration official at the U.S. border did not believe me that I planned to stay here temporarily. He kept asking questions about my family who live in the U.S., and unfortunately, he found a resume in my suitcase, because I had been planning to scout around for a job in the United States. So, he wouldn't let me in; I had to fly all the way back to my country, Brunei, immediately.
Now I'm wondering what happens next: Is this on my permanent immigration record? Can I ever come back to the United States?
The fact that you have been refused entry under the Visa Waiver Program (VWP) will indeed go on your permanent immigration record, and could impact whether you are allowed into the U.S. in the future.
But, unlike in a case where someone has actually been removed or deported from the U.S., VWP applicants do not typically face any automatic bar upon returning. These bars can last for many years.
If, however, you apply again to enter the U.S. on the VWP, chances are high that you will be denied when you complete the required application using the State Department's Electronic System for Travel Authorization (ESTA).
One of the ESTA questions asks whether you have ever been denied entry to the United States. (Lying on this answer COULD lead you to be permanently barred from entering the United States.)
Your "yes" answer is likely to lead to a denial, although there's no harm in trying. But you'd still risk being turned around at the border once again, even if your ESTA is approved.
That's not your last hope, however. You can still go to a U.S. consulate in your home country and apply for a tourist (B-2) visa. (See A B-2 Visa for Visiting the U.S. as a Tourist: Do You Qualify? for more information.) There, you'll have a chance to meet with a consular official and hopefully convince that person that your intentions are truly consistent with the visa you are applying for. The consular officer will enter notes about your travel plans into the consular database.
If your visa is approved, the Customs and Border Protection (CBP) officers at the U.S. port of entry can see these notes, which will serve as corroboration of your legitimate travel plans. Also see At the U.S. Border or Airport: What to Expect When Entering.
A final caution, however: Even after getting a visa, U.S. border officials can still refuse you entry; though it's less likely this time. But if they do so, they could potentially put a formal order of removal into your immigration record, thus creating a minimum five-year bar to your return. If you are truly, sincerely entering as a tourist for a short visit, with a return ticket, sufficient funds for you trip, and a visa, you shouldn't encounter any problems.