https://code.google.com/p/adb-fastboot-install/
Package containing the adb and fastboot binaries and a handful of simple shell scripts to drop them into the appropriate places on mac / linux. Nice.
http://peter.pisljar.si/projects.php
A Windows desktop client that allows downloading from the Android market. Requires Google username / password and some other data that appears to be sniffed off the device.
http://wiki.cyanogenmod.com/index.php?title=Full_Update_Guide_-_Nexus_One
Step by step instructions on how to flash the rom of the Nexus One. Only missing part is the udev rules for Ubuntu.
http://developer.htc.com/adp.html
I downloaded fastboot from this page for the HTC Google Nexus One.
http://www.randomphantasmagoria.com/firmware/nexus-s/
A list of ROM packages for the Nexus S, migrated from the xda-developers forum.
http://forum.xda-developers.com/showthread.php?t=883032
Really useful guide on how to unock and root the Nexus S. Easy enough to follow, and it actually works!
http://forum.xda-developers.com/showthread.php?t=1445570
A list of ROM packages for the Nexus S, the post says it has been migrated to a new location on a blog.