MobileJoomla for the iPhone
I was an early user of MobileJoomla, but struggled a little bit to get it to work the way that I wanted it to. This is a recap of some of the issues and settings that I've discovered make it work quite well on the iPhone, and thus a component I would definitely recommend.
Navigation-only on home page
MobileJoomla as a set of modules for each type of device that it supports. I noticed that there was no module for content like there was for the other modules. Apparently there's something about the iPhone's architecture that makes this problematic. As a result, there's nothing that can be done about this one without some rework. The site says that enabling component on home page will solve this, but at least with my iPhone even the navigation disappears. For now, I'm leaving this one alone.
Blank screens after the home page
Apparently there is an issue with some gzip-compressed pages. Turning off gzip compression seemed like a great idea but didn't solve the problem. Note: even with gzip compression turned off, my site loads fairly quickly, so I left it disabled.
MobileJoomla does report that image resizing is a known bug on the iPhone. What they don't explicitly say anywhere that I can find is that this is the culprit. By turning off image resizing, I now have content that displays on the site.
Difficulty with navigation
Because of the component I use for navigation (swMenuFree), my drop downs aren't working. I do have javaScript enabled, so that's not the issue. Although more of a workaround than a fix, I added breadcrumbs to the site.