London - HTC HD2, the latest smartphone from the Taiwanese company, is generating tremendous excitement worldwide. And why not? It boasts of the biggest touchscreen ever in a smartphone, the revolutionary HTC Sense UI and the super-powerful 1GHz Snapdragon chipset from Qualcomm.

In fact, the HD2 is being billed as the most formidable competitor Apple's iPhone has ever faced. But does it have what it takes to challenge the iPhone and usurp the title of 'the most coveted smartphone'?

Let us look at the specs.

HTC HD2 measures 4.74x2.64x0.43inches (120.5x67x11mm) (LxBxD), weighs 157gm (5.54ounces), is powered by Qualcomm 1GHz Snapdragon processor, runs on Windows Mobile 6.5 Professional OS and boasts of features such as a 4.3-inches capacitive touchscreen (that allows you to pinch, flick and swirl your fingers across the screen for intuitive navigation and also allows you to scroll, zoom in and out and flip through web pages, photos, spreadsheets and more) with 480x800 pixel resolution WVGA display, 5-megapixel camera (with autofocus, dual LED flash and video recording @30fps), WiFi, GPS, HSUPA, 3G HSDPA, GPRS, EDGE, Bluetooth 2.1+EDR, FM radio, HTML (Opera) browser (which promises quick, full-screen browsing with support for multiple pages), virtual touchscreen-based keyboard, G-sensor (like accelerometer in iPhone that senses if you rotate the device and changes the display to match), 512MB internal memory, microSD card slot, support for multiple audio and video formats, proximity sensor (to conserve battery life), ambient light sensor, FM radio, micro-USB connector, built-in stereo speakers, a standard 3.5mm headphone jack and a 1230 mAh Li-Ion battery that has enough juice to power the phone up to 380 minutes (talk time) and up to 490 hours (standby time).

The HD2, incidentally, is also the first Windows Mobile-based device to do away with a stylus for navigation and control.

The smartphone will also have integrated applications that connect directly for Facebook, Twitter and YouTube allowing users to access data more easily.

The HD2, which runs on the latest Windows Mobile 6.5, also promises to deliver "new customer experiences" through an easy-to-use interface (including large 'finger-friendly' icons that make item selection easier than on previous Windows Mobile handsets) and improved web-browsing capabilities.

Other amazing features about the HD2 are HTC Footprints (geo-tagging), Digital Compass and the NaviPanel and most importantly, the HD2 is the first Windows Mobile-based device to come equipped with HTC Sense UI, which makes multitasking possible.

HTC Sense UI, which is based on the principles: "Make it mine," "Stay Close" and "Discover the Unexpected," allows you to create his own environment, to conveniently communicate with contacts through multiple channels, while the innovative features make the difference between local phone and online disappear. HTC Sense slightly resembles the TouchFlo which we have seen on other models, but HTC Sense, which lets you create personal widgets and screens for your own personalization and is capable of multitasking, takes things just that little bit further.

On the other hand, the iPhone 3GS measures 4.5x2.4x0.48inches (115.5x62.1x12.3mm) (LxBxD), weighs 135gm (4.8ounces), is powered by ARM Cortex A8 600 MHz processor, runs on iPhone OS 3.0 and boasts of a 3.5-inches capacitive touchscreen with 480x320 pixel resolution display, 3.5-megapixel camera (with autofocus and video recording @30fps), WiFi, GPS, 3G, HSDPA, GPRS, EDGE, Bluetooth 2.1 with A2DP, HTML (Safari) browser, virtual touchscreen-based keyboard, accelerometer, ambient light sensor, proximity sensor, 256MB internal memory, 16/32GB internal storage, support for multiple audio and video formats, built-in stereo speakers, 3.5mm headphone jack, digital compass and a Li-Ion battery that promises to keep the iPhone juiced up to 300 hours (standby time) and 12 hours (talk time).

Well now that the specs are out, at first glance it would seem that the HD2 is a heavy-duty smartphone.

And, that's not surprising because to begin with, the HD2 is a smartphone with the biggest touchscreen practical - it sports a whopping 4.3-inch touchscreen with 480x800 resolution display (larger than the one featured by its predecessor HTC Touch HD, which itself boasted of a generously-sized display). In other words, things like web browsing or watching YouTube videos are, not surprisingly, more enjoyable on the HD2 than what one could expect from iPhone's smaller 3.5-inch TFT capacitive multitouch screen with 320x480 resolution display.

Thanks to the ultra-powerful Qualcomm 1Ghz Snapdragon processor, the HD2 is also road-ready for mobile internet use. This is somewhat welcome news as so many of the latest-generation Windows Mobile-based phones have just 528 MHz chips. It also means the HD2 promises to respond faster than the iPhone, which is powered by a slower ARM Cortex A8 600 MHz processor.

The HD2 also boasts of a 5-megapixel camera with autofocus and dual LED flash, which means that the smartphone promises to capture clearer, crispier images than the iPhone, which comes loaded with only 3.15-megapixel camera with autofocus (but no flash and no optical zoom).

The HD2 also has FM Radio unlike the iPhone and supports java games and applications which the iPhone can't.

The HD2 also supports two browsers - the default Opera browser and the Internet Explorer. Though the latter is slow, it supports Flash-based web pages, unlike the iPhone's Safari browser.

But, most importantly, the HD2 is the first Windows Mobile-based device to come equipped with HTC Sense UI, which makes multitasking possible (unlike the iPhone).

So far, so good. However, the iPhone is no pushover and it has not held the No.1 spot among smartphones ever since it was launched two years back for nothing.

For instance, the iPhone, which is lighter by at least 20gm and is smaller in size (115.5x62.1x12.3mm as compared to the HD2's 121x67x11 mm) sits both comfortably in your pocket as well as in your palm.

Unlike the iPhone, the HD2 also hogs a lot of memory and some lag time can be noticed when opening and switching applications.

Furthermore, the internal memory of the HD2 seems slightly lacking as at 448MB, you will pretty much find yourself running low on space soon enough. Which is unfortunate as considering that the HD2 is being billed as a heavy-duty multimedia phone thanks to its large screen, it hardly has sufficient space for storing media files, particularly videos. Of course, you could get a high capacity SD card for the SD card slot, but you will still want some files, apps and map data stored internally on the device.

On the other hand, the iPhone boasts of choices of built-in internal storage of 16GB or 32GB, though it lacks an expansion card slot.

And, let us not forget, iPhone users have access to a hot apps store with over 90,000 apps unlike the Windows Marketplace, which looks a bit bare at the moment. Besides, thanks to a service called MobileMe, iPhone provides features like phone tracking, remote data backup, remote data wipe and restore which the HD2 does not (though the HD2 does come with a PC back-up and restore feature).

But the biggest strength of the iPhone is perhaps its OS which remains unrivalled till date. The iPhone OS offers full multi-touch features and gestures unlike Windows Mobile 6.5 where there is no "real" multi-touch feature and one still needs to use a stylus for certain application, such as Windows Media Player. This is rather, unfortunate, considering that Windows Mobile 6.5 release was meant to be a move-away from the use of the stylus and toward more touch-friendly icons and buttons.

In fact, there isn't really much more to Windows Mobile 6.5. It's really just the same old Windows Mobile 6.1 with a smoother interface, touch-based navigation and some updated programs. Perhaps that's why Steve Ballmer recently referred to the OS as a "stop-gap."

However, the iPhone is not the 'perfect smartphone' either, though it is close to being one. For instance, it doesn't let you run multiple applications in the background, it doesn't have interchange batteries, it doesn't run widgets on your homepage that are live, it is devoid of an expansion slot and FM Radio, it doesn't show Flash, it doesn't support Java apps, and its camera, which besides taking pretty ordinary shots, doesn't have a flash and optical zoom, and so on.

In conclusion, the HD2 packs enough punches such as a bigger touchscreen, a faster processor and a better camera to challenge the iPhone but it lacks what we call the 'killer combo' to floor the iPhone.