Ramblings from another nerd on the grid
Please note that this toolkit will not prevent the installation of the service pack from CD/DVD, or from the stand-alone download package. This simply prevents the service pack from being delivered over Windows Update.
Get it @ http://www.microsoft.com/downloads/details.aspx?FamilyID=d7c9a07a-5267-4bd6-87d0-e2a72099edb7&DisplayLang=en
Thursday was a busy day at Microsoft.  RC1 for Longhorn is now out and available for download.