Nokia Lumia 900
The overwhelming demand for Nokia's highly anticipated smartphone - Lumia 900 - has forced the Finnish Company to push back the proposed UK release date for the elusive handset by as late as two weeks.

Nokia's anticipated Windows phone - the Lumia 900 - hits stores on 8 April. The phone, with an aggressively low $99.99 price tag, is already available for pre-order and is expected to provide Apple's iPhone 4S a real run for its money.

The iPhone and the Lumia will both run on the AT&T network, making at least that a level playing field for comparison.

The Lumia is the third smartphone in its series and although the 710 failed to create any waves, this model, which is a hybrid of the 800 and the N9.

Check out how the iPhone 4S and the Lumia 900 stack up against each other

Display: The Lumia 900 sports a 4.3-inch, 800-by-480 pixel AMOLED ClearBlack display, which is significantly larger than the iPhone's 3.5-inch screen; although the latter runs at a sharper 960-by-640 pixel resolution. Nokia's AMOLED will give you superior brightness and contrast levels, while the iPhone's Retina Display will offer you superior colour accuracy and image crispness.

Memory: Both smartphones ship with 512MB system memory (RAM) and neither supports a memory card slot for expansion. The iPhone 4S offers 16/32/64GB storage options, while the Nokia ships only the 16GB model.

Processor: The Lumia is powered by a single-core, 1.4-GHz Scorpion Snapdragon processor based on the Qualcomm APQ8055 chipset and a GPU core based on Adreno 205 chipset.

In contrast, the 4S boasts a powerful dual-core, 1 GHz Cortex-A9 processor based on the new A5 chipset, which Apple claims can deliver up to two times more power. It also adds a GPU core based on PowerVR SGX543MP2 chipset, which is claimed to deliver seven times faster graphics performances than the iPhone 4.

Operating System: The Lumia 900 runs on the Windows Phone 7.5 (Mango) platform, while the iPhone 4S flaunts the iOS 5. The Windows platform (WP7) brings a unified platform experience with social networking integration (Facebook and Twitter) at its core for an enhanced social experience. However, when it comes to apps, the Windows market is limited to just 65,000 apps and pales in comparison to the Apple App Store, which boasts over 500,000 apps. If you want a smartphone to play particular apps - like Cut the Rope, Draw Something, Pandora, Temple Run or Words With Friend - then the iPhone is made for you.

Camera: The Lumia 900 sports an eight megapixel (3264x2448 pixels) rear camera with Carl Zeiss optics, autofocus, dual-LED flash, geo-tagging and the ability to record videos at 720p and 30fps (frames per second). It also adds a 1.3 megapixel front-facing camera for video calls.

In contrast, the 4S also has an 8 megapixel rear camera with similar features and includes a secondary VGA camera for video calling (over Wi-Fi only).

Connectivity: While both smartphones run on AT&T, the biggest difference is the Lumia 900 uses AT&T's 4G LTE network, while the iPhone 4S uses 3G. It may be noted that although the iPhone 4S may now show a little "4G" icon, HSPA+ 14.4 is certainly not 4G and LTE is almost five times faster than HSPA+.

Battery: Boasting a powerful Li-Ion 1830 mAh battery, the Lumia 900 truly holds the upper hand with up to 300 hours of standby and 60 hours of music playback. In comparison, the 4S has a Li-Po 1432 mAh battery, delivering up to 200 hours of standby and 40 hours of music playback.

Price: Price is definitely going to be an important factor for prospective consumers. The $100 Lumia 900 is streets ahead of most other models, if you're talking about reasonably priced devices. Surprisingly, the amount of features packed in for the price makes this phone surefire bang for your buck!

On the other hand, the 4S is priced in the range of $199-$399, based on the storage size. So, if you are willing to spend those extra bucks to put your creative skills to test in a game or use graphic apps for drawing something, the iPhone 4S offers an unbeatable app experience.