Its as easy as opening Safari on your iPhone/iPod Touch, and browse to jailbreakme.com. Thats it! Scroll down, and hit “Install AppSnapp”. Safari should disappear, and pop you back to the Home screen. Wait patiently for a minute – don’t touch anything til it pops you back to the Slide to Unlock screen.
Slide to unlock, and Installer.app will be installed on your iPhone/iPod Touch! You should prob install BSD Subsystem, Community Sources, and OpenSSH, and upgrade Installer.app if needed.
Erica Sadun from TUAW also refreshes the good tip that combining Open SSH and sshfs (part of Mac Fuse) allows you to drag and drop files to/from your iPod Touch/iPhone directly from Finder.