For those interested in iPhone 4, you can register your interest at Maxis and DIGI and as the iPhone 4 arrived in Malaysia, you will be among the first to be offered to buy one. If you're interested to register with Digi, you can go directly to their website here. For Maxis, as shown below, you can go directly to their website and search for PHONES & iPHONE.
You will see the page below. Scroll down till you found the registration form.
Select whether you are planning to register to personal use or corporate use.
Update your particular details and press Submit. You're done. And just wait till Maxis contact you when the iPhone 4 is available in stores.