
First, we have the SMC Update 1.0 for the MacBook Air, available here, which is supposed to fine tune the speed and operation of the internal fan of Apple's thinnest laptop. This application requires you to download 551KB of data, requires Mac OS X 10.5.1 or later, and will end up in the Applications/Utilities folder.
At last, there's the 1.0.4 firmware for the new 2GB iPod shuffle, delivering various unspecified bug fixes, as well as "enhanced support". This one can be downloader from this page.