The last days I tried to access my PGV site from an iphone, but it was really no fun. So I tried to add some files for a basic iPhone support. All it does is displaying the individual page and some basic information (besides searching etc.). I know there is no support for displaying families, sources etc. I also haven't tested the code on sites with more than 1 gedcom file, data an users with restrictions and some other conditions that are not used on my personal site. The main goal was to not modify any original file, so I needed to copy some functions. I know that my php code is not too good, but - it works!
Feel free to use the attached file or download the files at www.bluescreen.de/pgviphone und use them as you like! Any hints and comments are welcome. The files were tested on PGV 4.2.2, an update (if nescessary) for 4.2.3 will follow the next days.
I know there is a different solution that is based on a new mobile theme. As far as I understand you have to add a new "mobile user" and modify some original files, which I don't like...