Apple also released a firmware update for iPod touch, bringing it in line with most version 2.2 updates for iPhone released a little while ago. It doesn't appear, however, that iPod touch users get the enhancements to the Maps app that iPhone users do. (Thanks, Guillermo!)
The update contains enhancements to Mail, fixes connection issues with WPA-secured wireless networks, improves Safari stability, and includes a new preference to turn off auto-correction for typing.
Also, podcasts are now available for download from within the iTunes app, and pressing the Home button from any home screen will now take you to the first home screen.
Several security enhancements are included, too, updating CoreGraphics, ImageIO, networking, Office Viewer, Passcode Lock, Safari and Webkit. A complete list of security updates is available on Apple's website.
The update is available by clicking "Check for Update" with your iPod selected in the Devices area of the sidebar in iTunes.