Apple's latest bout of knowledgebase updates includes a number of small pointers for people using their iPhones. These are basically simple how-to steps for people who are managing their SIM cards, connecting to data networks, and managing applications purchased from the App store. Apple also has a tip for iDisk users trying to share large numbers of files.
iPhone applications may sometimes either not open, or you may have problems synchronizing them to your iPhone. In these cases there are several things you can try, including reauthorizing iTunes and reinstalling the iPhone application.
Apple has a SIM eject tool for the iPhone, but a standard paper-clip or similar device can also be used. This article covers how to eject the SIM.
UK users have the option of using a Tesco SIM card, and Apple's suggestion is to review their support documentation for troubleshooting problems.
This article covers an issue where long access point usernames and passwords may prevent the iPhone from connecting, resulting in a "PDP authentication failure" message.
This is standard behavior, because by default "Disk Mode" is not enabled for the iPod. If the iPod cannot be recognized in iTunes at all, see this Apple KB article: http://support.apple.com/kb/TS2050
This article shows you how to enable voiceover on the latest iPod shuffle, which needs to be done through iTunes. Apple also has provided updates to voiceover, and covers how to install them from here.
Apple's iDisk web sharing does not support more than 500 items. If you have more than this you will need to reduce the number, otherwise the number of files you have available will be truncated. The article includes tips on how to better manage large numbers of files so they can be accessed.