how to install kernel source 2.6.8

[Mike McClain <mike.junk@nethere.com>]

I've a mostly etch system and wanted to try the 2.6 kernel.

mike@/deb40a:~> uname -a
Linux playground 2.4.27 #1 Mon Dec 24 13:55:08 PST 2007 i586 GNU/Linux

The only un-commented lines in /etc/apt/sources.list are:
deb http://ftp.us.debian.org/debian/ etch main contrib non-free
deb-src http://ftp.us.debian.org/debian/ etch main contrib non-free
deb http://security.debian.org/ etch/updates main contrib
deb-src http://security.debian.org/ etch/updates main contrib
deb http://www.backports.org/debian etch-backports main contrib non-free

root@/deb40a:~> apt-get update
root@/deb40a:~> grep "Package: kernel-source" /var/lib/dpkg/available
Package: kernel-source-2.4.27
Package: kernel-source-2.2.25
Package: kernel-source-2.6.8

root@/deb40a:~> apt-get install kernel-source-2.6.8
Reading Package Lists... Done
Building Dependency Tree... Done
Package kernel-source-2.6.8 is not available, 
but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
E: Package kernel-source-2.6.8 has no installation candidate