How much internal storage does the iPhone have? Can it be expanded? Does the iPhone have a MicroSD slot?

The original iPhone has 4, 8, or 16 GB of internal flash memory and the iPhone 3G has either 8 GB or 16 GB of internal flash memory. The memory cannot be expanded in any iPhone models.

A number of high-end phones from Motorola, Samsung, LG, Nokia and others have a MicroSD slot that makes it possible to inexpensively add more memory to the device, but the iPhone does not have this capability.

For readers not familiar with the MicroSD standard, it is a tiny flash memory card -- "about the size of a fingernail" -- designed specifically for mobile phones to hold "music, movies, video clips, pictures, ring tones and more". For more information regarding the history of the standard, please refer to PhoneScoop.

Photo Credit: Kingston.

Does the iPhone support Bluetooth?

Yes. The iPhone supports Bluetooth 2.0, as well as Wi-Fi (802.11b/g) and the Cingular EDGE network. However, the Bluetooth functionality is somewhat restricted. Version 3.0 of the iPhone OS, promised for release in "Summer 2009" is promised to have substantially improved Bluetooth support including "peer to peer connectivity" and support for accessories. It reportedly will have Internet tethering via Bluetooth as well.

Can the iPhone use iPod accessories?

The iPhone has a standard USB-based iPod "dock connector" port on the bottom, so the majority of iPod accessories that are compatible with modern iPod models should be compatible with the iPhone as well.

Can you use the iPhone with an external keyboard?

On February 5, 2007, with the initial publication of the iPhone Q&A, EveryiPod.com reported:

Although no official information is available, it could be possible either for Apple or a third-party accessory manufacturer to create a keyboard for the iPhone either using the USB-based "dock connector" port or wirelessly via Bluetooth 2.0 (although the iPhone currently does not support peripherals via Bluetooth). Of course, for a third-party manufacturer to develop a keyboard it likely would require Apple's approval and cooperation.

A simple folding keyboard -- as have been available for other handhelds for years -- could be created for the iPhone, which might be of particular interest for those who appreciate tactile feedback.

Additionally, a "virtual laser keyboard" (shown at left) theoretically could be developed as well. Photo Credit: I-Tech

On March 17, 2009, Apple previewed version 3.0 of the iPhone OS and the company now plans to provide the previously mentioned approval and cooperation for accessories via a new "External Accessory" framework. This framework will make it possible for hardware accessories to communicate with the iPhone via the 30-pin dock connector or Bluetooth.

Amazingly, as first spotted by the TUAW blog, some very clever hardware experts from Perceptive Development Labs "developed a hardware and software solution that allows infrared keyboards to be used for typing on the iPhone" even without Apple's framework using version 2.0 of the iPhone OS.

This video shows the details:

Very impressive. When version 3.0 of the iPhone OS is finalized and released, it is essentially certain that third-party keyboards will be offered, no tweaking or hacking required, even though Apple did not explicitly mention that keyboards would be supported.