The iPod touch Generation 2 is similar in features to the iPhone 3G, but lacks phone features, mobile phone networking, GPS, and a camera. While the back of the iPod touch Generation 2 is made of stainless steel (instead of plastic), its shape is similar to the iPhone 3G.
The iPod touch Generation 2 featured a multi-touch 3.5-inch display with 320×480 resolution, an accelerometer, ambient light sensor, Wi-Fi (802.11b/g), and 8, 16, or 32 GB of flash memory.
Compared to the original iPod touch, the Generation 2 model adds external volume controls on the left side of the device, an integrated speaker, external microphone (supported via the Apple Earphones with Remote and Mic), support for the Nike+iPod Sport Kit, a Genius feature to dynamically create playlists, and shaking the device to shuffle songs.
The iPhone 3G is similar to the original iPhone in functionality, but adds 3G cellular support and GPS. Although it features the same 320×480 resolution screen, the case is slightly thicker (0.02-inch) than the original, and had a plastic (rather than aluminum) back available in black or white. Both models were available in 8 GB or 16 GB, but the white iPhone 3G was only available in 8 GB.
The GPS functionality allowed the 2.0 megapixel camera to support geotagging. The iPhone 3G uses the same multi-touch interface, accelerometer, ambient light sensor, and proximity sensor capabilities as the original iPhone, except it has two proximity sensors compared to one in the original.
The back of the iPhone 3G has the most curved shape of any iPhone design to date, and has been the only “flagship” iPhone model to ship with a plastic back.
The original iPhone was officially announced on January 9, 2007, and was released on June 29, 2007. The original iPhone was available in 4, and 8 GB capacities, with a 16 GB capacity released on February 5, 2008. Soon after the original release, Apple dropped iPhone prices by $100. As a concession to early adopters (after criticism), Apple offered a $100 store credit. I used my store credit to purchase the $99 Apple Bluetooth Headset.
The original iPhone introduced the “multi-touch” display that allowed control by dragging one or more fingers across the glass display, although no interface controls required multiple fingers in the iPhone OS 1.0. This iPhone has sensors including an accelerometer (to detect landscape or portrait orientation), an ambient light sensor (to control screen brightness), and a proximity sensor (to turn off the display when held to the ear).
Other features include Wi-Fi (802.11b/g), EDGE, Bluetooth 2.0, and a 2.0 megapixel camera. The case is 2.4 inches by 4.5 inches, is 0.46-inch thick, and weighs 4.8 ounces.