This is more very exciting news and should not pass without great fanfare. Linux for the DS is here!
The DS Linux team has been making a lot of progress lately. Not only is a kernel booting on the DS, but the SASH shell is now running along with a few text games. ROM images and patches for DS Linux can be downloaded in Downloads Section.
Although I'm not seeing a tutorial to help newbies port the Kernel, many answers to midlevel questions can be found in this forum thread...
Thanks to Malcolm Parsons suggestion to update the banner to reflect "Linuxed."