Apple's iPhone 4S has been extremely popular since its debut, so popular in fact, the Chinese debut in January 2012 nearly caused a riot when the six licensed Apple stores sold out of the devices. Still, it does cost $200, so if you're not quite ready to spend that much, you should consider the iPhone 4. The difference may not be enough for you to decide to spend the extra $100, but at least you can factor that in to your next smartphone purchase.

Besides the price, iPhone 4 and iPhone 4S do like exactly alike. It's inside the minimalistic, all glass exterior where you'll find all the changes. iPhone 4S features a new processor, improved camera optics, more internal storage, a dual-band 3G radio (world phone), improved GPS tracking, video mirroring and 1080p video capture. So for $100, you get the iPhone 4's 1GHz processor, five megapixel rear-facing camera, 720p video capture and no ability to wirelessly transmit your videos to an HDTV through the Apple TV. You can still plug the iPhone 4 into an HDTV with the Apple Digital AV Adaptor, however ($40).

Lastly, there is the digital voice recognition software called Siri. It's one of the iPhone 4S' main selling points, and it can send your emails, make appointments or search for a breakfast joint by listening to your voice. Again, there are apps that can make up for some of these abilities on the iPhone 4, but Apple says the iPhone 4S' new CPU is what allows it to run Siri. Without the dual-core system, Siri would be too taxing on iPhone 4's system and battery. If you're shopping for a new smartphone, the iPhone 4 is a great choice, just remember the new store bought versions have only eight gigabytes of internal storage. Both devices are on Sprint, AT&T and Verizon with a new two year contract and data plan. Tell us in the comments what you prefer about either the iPhone 4 or iPhone 4S.  

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