Select "None" as a "Payment Method" section during the registration
I still think getting a US iTunes Account is still the best option as it is completely unrestricted. You can create a US account without a credit card, using the same method above but select US instead of Brunei. You will need to buy gift cards online though, and I have bought iTune gift cards from both PC Game Supply and Jerry Cards with good results so thus far. See which works best for you and join the ecosystem that has yet to be rivaled (especially outside the US).
A ‘live’ / non-Skype Corner Geeks recording this week as I sat down with @mfirdaus as we discussed the Brunei Apple App Store while also passing him the InstallESD.dmg file for Lion. We hope that this is the start of more services being opened to Brunei and perhaps a legal way for people to get music, movies and TV shows in the future.