The gang at "iFixIt' have torn down the iPhone 4. They say Apple definitely spent time giving the phone a thorough makeover, meticulously changing every little facet.
You can find the complete teardown at http://www.ifixit.com/Teardown/iPhone-4-Teardown/3130/1 . However, here are some of the highlights:
° Like the iPhone 3G and 3GS, there are two silver Phillips screws at the bottom of the phone. But removing these screws releases the rear case instead of the front glass, giving you immediate access to the battery.
° Unfortunately, the LCD panel is very securely glued to the glass and digitizer. If you break the glass, you'll have to replace the glass, digitizer, and LCD as a single assembly.
° The 3.7V, 1420 mAh Li-Polymer battery is not soldered in place, and very easy to remove.
° The iPhone 4 sports two cameras -- a 1.3 MP front-facer, and a 5 MP beauty on the back. Both are located on their own independent boards, making it possible to physically remove the cameras without damaging the phone.
 ° The phone uses the 1GHz ARM Cortex A8 core, much like its bigger sibling, the iPad.
 ° Unlike the iPhone 3GS and iPad -- which are both equipped with 256 MB of RAM -- the iPhone 4 has a whopping 512 MB.
° The AGD1 is the new 3 axis gyroscope that we believe is designed and manufactured by ST Micro for Apple. The package marks on this device do not appear to be the currently available commercial part, L3G4200D.
° In what can only be described as a work of genius, Apple has integrated the UMTS, GSM, GPS, Wi-Fi, and Bluetooth antennas into the stainless steel inner frame.
 ° Broadcom provides both a BCM4329FKUBG 802.11n with Bluetooth 2.1 + EDR and FM receiver and a BCM4750IUB8 single-chip GPS receiver.
"iFixIt" has identified chips from Broadcom, Cirrus Logic, Numonyx, Samsung, ST Micro, Skyworks, Texas Instruments, and TriQuint.
