Rather than supporting the highly closed iOS platform that is designed to be locked down, just port to Android.
There is a far wider selection of phones available than the iPhone, including some quite low cost ones ($150 or less without contract) as well as high end phones with all the gizmos. Android is fundamentally an open source platform and by all accounts is reasonable to develop for (whether in Java or C/C++). One example of openness: I've just bought an 18 month old G1 phone that originally ran Android 1.0, and can upgrade it to the latest Android 2.2 quite easily via CyanogenMod, whereas the original iPhone can't run iOS 4. Most Android phones are very reflashable and open (some can run Debian).
Android has a great combination of mass market phone apps and Linux tools. It lets me easily do things like run an SSH daemon plus rsync on the phone, so I can back it up exactly as I do with Windows and Linux boxes, using the excellent rsnapshot - not a mass market application but it shows how open it is.
It's quite likely that Android will overtake iOS in market share within a few years. The pace of new Android phones being introduced is increasing (next 6 months will see candybar, various Qwerty sliders and more), and Android is winning market share against iOS, subject to various new product introductions: http://www.fiercemobilecontent.com/pages/u-s-smartphone-m... shows an increase from 2.5% to 13% while Apple's market share remained essentially the same at 24.4%.