While this is not quite iPhone development advice, it is advice using the iPhone to help you develop with Unity by creating a complete iPhone viewable offline manual.
First, download the iPhone app “AirShare” from the App Store (currently $5.99USD). Next, launch the AirShare app on your iPhone/iPod Touch and connect to it from your computer. After that, create a new folder on your iPhone/iPod Touch and then locate your Unity application folder (probably in Applications/Unity/). Finally, copy the entire “Documentation” folder from your Unity application folder to the folder you created on your iPhone/iPod Touch.
Once the copy operation finishes, you should then be able to use AirShare to view the entire documentation for Unity (including the manual and scripting reference) on your iPhone/iPod Touch without an external connection of any kind, complete with accompanying images and hyperlinks, along with full multi-touch support.
It may not be a true, printed manual, but it’s about the closest you’ll find in a handy, portable format. 8)
Well, after nearly a full day of getting reacquainted with the Unity documentation using an iPod Touch as a reader, I have to admit that the documentation is not nearly as difficult to follow as I’ve criticized it for in the past.
By eliminating the overhead of bouncing back and forth between Unity and a web browser on the same machine, the entire process of learning from the documentation and following along in Unity becomes much, much simpler.
Before now, I had been relying on a crude index card based scripting reference as a means of syntax checking.
I can now finally retire the stack after all this time! 
Does that system allow changing the font size of the pdf or do the sides get cut off when you zoom?
sides get cut off when you zoom (it does not wrap), though double tapping on an area of text will zoom in on that column only, which makes nearly all text a comfortable viewing size…
btw… this was an excellent tip…thanks for pointing it out… though i would still love to have a printable scripting reference that i can scribble on…
It does cut off, but double tapping scales it to width where necessary. Once scaled, the content pretty much retains its width for the rest of the page. I do recommend viewing the manual in landscape mode to keep the text and images at comfortable size while reading.