any iphone used outside the AT&T line or with any LINE without Apple's authorization is consider void .. so no matter what you do , your warranty will not be valid. Or u can wait for iPhone to be officially launched in Australia .. then you can get the warranty..
yes, all unlock programs/ method ... are used to unlock iphone so that it can be use with ANY lines ...
unlocking iphone .. is safer than sex with condom ..
so yea..if anything happen .. just restore and unlock again ...
how to restore? how to unlock ? what you need..? .... www.google.com is all that you need ..

well for ur question... u r using 3 rite? i stay in melb for 3 years d..just got back,
btw..in order to use ur sim card on other phone..there is always a solution to it..
just go to 3 store and checkout with those ppl. cause my friend did find out a way that solve the prob

well,i'm using Vodafone on my iPhone.... it works like a charm..... i dunno about 3 though, but Optus is good to go too..... u have any friends that owns a iPhone? maybe u can try by putting your simcard into it, make a couple of calls to see if it works well..... good luck.... haha....

So once i unlock .. can be used in Australia and Malaysia ?

So if i screw up the unlocking procedure ... i can restore and get back my warranty ? oo i tot it will be like f-ed up like a brick or something ....

Sry 1 more question, I juz found out that a particular provider in OZ ( 3 - the one im using ) doesn't allow its sim card to be used on NON 3G phone ... Iphone is not 3G right ? So just wondering ... original Iphone .. without unlocking .. can i use it without any simcard and use it as itouch ?

1. yup, once unlocked, u can use anywhere u like as long the simcard / telco is supported.

2. if wanna send for warranty, maybe u need to restore to factory settings using the same software u perform unlock. mmm...in recent days i've never heard bout bricking iPhone (only heard in its early days of unlocking). but i can't assure anything. bout the warranty, take an example of AT&T iPhone:

3. without unlocking, u CAN'T use as iPod Touch. u can only do that after performing hacktivation (bypassing the activation screen, not the SIM-unlocking part). simply put, just perform unlock and u'll get an iPod Touch if u don't put the simcard inside. unlocking softwares already automates all the process (bypassing activation, installing SIM unlock, installing jailbreak) with one simple step.