THE aerial doesn't work when you hold it in your left hand - but iFans are still excited for the release of the new iPhone.

The Iphone 4 is the thinnest smartphone in the world and includes more than 100 new features.

It has a five megapixel camera and the highest resolution display ever built into a phone. It also has a three-axis gyro and allows up to 40 per cent longer talk time.

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But this latest Apple gadget is not without its flaws. A glitch in the design has caused the phone's antenna to lose signal when held in the left hand. But Apple has already promised to supply every iPhone 4 buyer with a free "bumper" case - which will address the fault.

Telstra area general manager Mark Sweet said he was looking forward to bringing the next generation of iPhone to Australians on the country's largest and fastest national mobile network. Rival telco Optus is also plugging the device, claiming the company's dual band network means those in the Northern Territory will be able to use the iPhone to the full capacity for the first time.

But amidst the hype, Apple accessory makers expressed concern that Apple's promise to give iPhone 4 buyers free cases could cripple the industry.

Successful Melbourne-based iPhone accessory maker Cygnett has made 36 cases for the new-look smartphone, but chief executive Gary Newman said Apple's decision to give away a free case with every phone could significantly eat into accessory purchases.

"Every case you give away is one case that probably won't get purchased,'' Mr Newman said.

"But it will be a question of how many people are satisfied with a black bumper on their phone versus how many people want to personalise it.''

The offer for a free case will be available until September 30.

Apple recently called the new phone the "most successful'' Apple product to date after selling 1.7 million models in three days.

The phone costs $859 (16GB) or $999 (32GB) outright.