There are many differences between the new iPhone and the old iPhone. Below you will find reviews and pricing of the iPhone 4 and the iPhone 3GS to help you decide if the new iPhone is worth purchasing or upgrading. While not a free cell phone, the iPhone 3GS will continue to be sold at a discounted price with iOS 4 operating system but now only 8 GB of memory.

There are many upgraded features for the iPhone 4 when compared to the previous model. One of the new features is a much slimmer width of 0.37 inches. This is 24% thinner than the iPhone 3GS. Another upgrade is for the battery, talk time is increased by 40% on the iPhone 4. Finally the addition of the gyroscope technology allows for six axis motion sensing, this is in combination with the accelerometer.http://gadgetwidgets.com/iphone-4-vs-iphone-3gs-comparison/

The gyroscope In addition to the accelerometer that was featured in the iPhone 3GS, has now upgraded the iPhone 4 to six axis motion sensing software. This gyroscope adds another three axis gryo that controls pitch, roll, and yaw, also a rotation about gravity. This is a default feature on every iPhone 4 and requires no extra cost or applications.http://www.youtube.com/watch?v=ORcu-c-qnjg

Pricing and availability of the iPhone 4 and iPhone 3GS in the US are compared below. Keep in mind that as of June 7th, AT&T (US provider) charges a $325 early termination fee on the two year contract.

Tethering on the iPhone 3GS and iPhone 4 (but not iPad) is allowed with the new AT&T data plans that took effect June 7th.http://www.product-reviews.net/2010/06/04/new-iphone-4g-no-ipad-tethering-say-att/