Apple has released it's new OS for the iPhone and iPod touch, and, as often with this sort of release, the OS includes a number of security fixes. There are more than 40 fixes altogether (details here), including a number that affect WebKit, the page-rendering framework used by Safari. A quick comparison of the fixes in this update with those of the recent Safari 4.0 update show a number of similarities, since the code base for the iPhone OS and Mac OS X are the same. The iPhone update contains many other fixes, though, for elements such as CoreGraphics, Exchange, IPSec, Mail and Telephony.
This update is only available through iTunes. It is free for iPhone users and costs $10 for iPod touch users.