On Wednesday, amid the iPhone 3.0 release craziness, Apple released an update to the Safari 4 browser.
The Safari 4.0.1 Update (a 43.8 megabyte download) is reported by Apple to address incompatibilities between Safari 4.0 and certain features in iPhoto ’09, including Places and Facebook publishing.
It can be downloaded via the Software Update control panel on your Mac. At the time of this posting, there was no stand-alone updater at the Apple website.