All SharePoint websites by default have a mobile version. You can get at it by pasting /m behind your normal URL. If your website is at http://www.mysharepointwebsite.com/ then the mobile version is at http://www.mysharepointwebsite.com/m/. The idea is that you can use the mobile version from devices with limited capabilities and bandwidth.

The result you get is (by design!) extremely basic. It’s a text-only rendering with very limited functionality.

Bit if you have an iPhone, you don’t need to limit yourself to that. It’s perfectly possible to use most of SharePoint’s functionality from an iPhone. Here is a screenshot from our company SharePoint Intranet site on my iPhone:

Most things (even the “Ajax-y” parts like collapsing and expanding lists) work just fine, and since the iPhone is capable of displaying most commonly used document formats – including pictures, PDF files, Word documents, and Excel spreadsheet, even in the new Office 2007 format – you can look at documents and pretty much use most of the features of any SharePoint web site.

It’s not very fast, and you probably do not want to do this a lot over your 3G connection (SharePoint web pages can get pretty big…), but it does work, and if you have a fast WiFi connection it’s actually not too bad.