[UPDATE - Telecom has now announced its own Micro-SIMs, and iPad plans]

The fourth generation iPhone hit the shelves in the US, Japan, France, Germany and the UK today, provoking another wave of Applemania. US media reports say there were still queues at Apple stores hours after they opened.

The almost unanimous critics’ verdict: it’s the best smartphone on the planet - see the review round-up end of article for more.

(Separately, Apple has released version 4 or iOS 4 of the software that runs iPhones this week. This free upgrade can be installed on an iPhone 3GS, but not with all the features available for iPhone 4 owners. Read more about iOS4 here.)

In July, iPhone 4 it will be available in 18 more countries in July  and in September another 40.

New Zealand was among Apple's official list of countries to get the iPhone in July, but yesterday  a Vodafone NZ rep still not confirm for NBR when the iPhone 4 would arrive here. The official word is still "within a few months".

Uh-oh XT
Nevertheless, iPhone 4 is excellent news for Vodafone.

For a key feature of the iPhone 4’s squarer design is that it’s 24% thinner than its predecessor.

To help accommodate the super-thin design, Apple has become the first major phone maker to switch to a totally new type of SIM card called a MicroSim (also used by the 3G version of the iPad) which, as its name suggests, is physically smaller than the SIMs used by most today.

That means Kiwi iPhone users will no longer be able to simply pop an XT SIM card into their Apple handset then connect to Telecom’s network (and, indeed, a certain Telecom division will not be able to sell the iPhone 4 on the sly, as it does with today’s model).

Fanboys point to Telecom’s plan, vague expressed by one of its staffers, to release a MicroSIM for XT. But the telco has no official timeline. And with no cellphones in its line-up (or near future line-up) that require the new format chip, it lacks the necessary (if thin) excuse for releasing a MicroSIM.

(It is possible to execute a "scissor hack", whereby a traditional SIM is quite literally cut to fit a MicroSIM slot. If you're comfortable with a cleaver, checkout this illustrated guide. But I'm not sure whether average customers or corporates will be comfortable with the cut-up.)

All 3G, all the time
The other big bonus for Vodafone: iPhone 4 supports 900MHz, the 3G frequency the mobile operator uses nationwide (the previous model only supported 2100MHz, the frequency Telecom and Vodafone use in urban areas; iPhone 4 also supports the 850MHz frequency used by Telecom nationwide).

A quick recap of iPhone 4’s headline features:

• a 9.3mm thick case, 24% thinner than the iPhone 3GS. Apple claims this makes the iPhone 4 the world's slimmest smartphone
• a front-mounted camera for videoconferencing, and video chat software
• the ability to record video in high definition 720p
• a move to a micro-SIM card, as used by the iPad (but none of today’s cellphones, making it harder for Telecom users to network hop; more on that here)
• rear camera upgraded to 5 megapixels with LED flash
• the same size screen (3.5-inch) but, at 960 x 640, four times the pixel count of the current iPhone 3GS and, according to Apple, the highest resolution smartphone display on the market
• HSPDPA/HSUPA support (7.2Mbit/s down and 5.8 Mbit/s up)
• space saved by micro-SIM has been used for a larger battery, which Apple says increases talk time by 40% to seven hours

Here’s what the most influential US critics made of iPhone 4 this week:

Walter Mossberg, The Wall Street Journal
What’s hot:
“With the front-facing camera, and clever new software called FaceTime, Apple has brought simple, high-quality video calling to mobile phones, albeit, for now, only over Wi-Fi and only among iPhone 4 owners.”
“Dramatic redesign ... radically sharper screen.”
Pointed criticism:
Only available on one phone network in the US.
Verdict:
"In both hardware and software, it is a major leap over its already-excellent predecessor, the iPhone 3GS [that] keeps it in the lead in the smartphone wars.”

David Pogue, The New York Times
What’s hot
“The first thing you notice is the new shape. Despite a beefier battery (16% more likely to last a full day), a faster processor and upgraded everything, the new model is still noticeably thinner and narrower than before. How is that possible? It’s beautiful ... it feels solid and Lexus-like”.
Pointed criticism:
“It’s now impossible to tell by touch which way it’s facing in your pocket.”
“The new metal mute and volume buttons are much stiffer”
Verdict:
“The iPhone is no longer the undisputed king of app phones. In particular, the technically inclined may find greater flexibility and choice among its Android rivals. [But] if what you care about, however, is size and shape, beauty and battery life, polish and pleasure, then the iPhone 4 is calling your name.

Melissa Perenson, PCWorld.com
What’s hot:
“The new ‘Retina display’ - so named because it surpasses the number of pixels the human retina can process - greatly improves the sharpness, clarity, and visible detail of images. I'd liken the magnitude of difference to that between a standard-definition 480p DVD and a high-definition 1080p Blu-ray Disc: When you view both on an HDTV, the differences are striking. And once you see them, you can't go back.”
“[Apple delivers on the promise of making multitasking work smoothly.”
Pointed criticism:
None.
Verdict:
“A must-have for anyone with an original iPhone or iPhone 3G. And people who have an iPhone 3GS will find this a worthy upgrade, too.”