A couple of creative engineers have developed a method to connect a infrared Keyboard to an iPhone. Furthus input text using 2.0 SDK-safe code.This is a Project that is not reaqdy for Prime Time just yet.!

The work is built on a 1200 baud modem that connects

 to the iPhone via the headphone port. This allowstwo-way transmission of data using frequency shift keying, the same method used in early modems. This modem was modified to accept input from infrared and USB connected devices, allowing the use of a keyboard. Further, a 2.0 SDK-compliant terminal app enables text input.

The hack is interesting in that it does not require jailbreaking the iPhone to work, but it is far from a general input device that some users would like to see. Apple is opening up the iPhone OS to let peripheral devices connect via the dock connector or Bluetooth, so an obvious solution is for Apple to include a system-wide keyboard driver in its Bluetooth stack. 

Perceptive Development plans to release schematics and source code for those wanting to implement its solution.