Apple has release iOS 4.2 for the iPhone, iPad and iPod touch. This update brings a number of new features to iOS devices, and notably adds such features as folders and multi-tasking to the iPad, which had previously been running iOS 3.2.
This update features a number of security fixes, patching 46 vulnerabilities, such as more than a dozen fixes to WebKit, the HTML rendering framework, and a number of fixes to CoreGraphics, FreeType, Mail and Telephony.
This update is available via iTunes when syncing a compatible device. More information about the security fixes is available here.