Unlocking the Bootloader on a Nexus One with S-On I'm interested in rooting my (Very recently bought) nexus one, and installing Cyanogenmod over Fastboot.

However, on the boot screen of my device I've noticed the first line tells me that security is on, which disables the USB Interface in the bootloader:

Nexusone PVT Ship S-ON


On the Cyanogenmod wiki page on Fastboot, the instructions say before starting that I need to have a device with S-OFF. However, I've got the impression from trawling through forums that Nexus One phones generally come pre-set with S-OFF (in contrast to the one I just bought).

How do I turn off the Security mode on the Nexus One? i.e. How do I change S-ON to S-OFF?
Nexus Ones do not ship with 'S-OFF', they ship with a "locked" bootloader which then must be unlocked. You can actually use fastboot to unlock the bootloader, just run fastboot oem unlock on your PC using ADB (Android Device Bridge). MoDaCo has a post here with complete instructions and a multi-platform download of the needed tools.