iGoogle for iPhone:
Google created a version of iGoogle optimized for iPhone, that displays all the gadgets and feeds from tab in a single column. To switch to another tab, choose a name from the drop-down displayed at the bottom of the page.
The iPhone interface has a public URL: http://google.com/ig/i, but iPhone users will be automatically redirected to this URL.
The standard mobile version of iGoogle available at http://google.com/m is much more limited: it only displays feeds and a very small number of gadgets, you need to manually add items to your page and you can't change the number of items displayed from a feed. Another limitation is that it only works in the US.
{ via Blogoscoped Forum. The image doesn't show a real iPhone. }