I have came across this post several times and feel I must clarify for those that may get mislead.
The iPad Camera Connection Kit does NOT work if the dongles are plugged into the iPhone or iPod touch. I have tested it on an iPhone running 3.1.3 and an iPhone running beta 4.0 OS. Both say this device is not supported.
YES you can connect the iPhone into the iPad using the usb dongle, which is what the second poster is referring to. Very different from what the OP was asking about.
I personally would love to see these dongles work directly on the iPhone for the audio interface possibilities, and perhaps the external usb keyboards.