I thought I'd share a procedure that I've gotten pretty good at and that is REALLY easy for those of you looking to upgrade your kernel after using Installer. This procedure is specifically for those of us already booting off of an SD card as set up by Installer. I couldn't find instructions for doing this anywhere, so I apologize if I'm stating the obvious.
# mkdir /mnt/BootMnt
# mount /dev/mmcblk0p1 /mnt/BootMnt/
# wget http://sheeva.with-linux.com/sheeva/README-188.8.131.52
# chmod 755 README-184.108.40.206
# ./README-220.127.116.11 --rootkernel
# mv /boot/sheeva-18.104.22.168-uImage /mnt/BootMnt/uImage
Bask in your success!
*Edit* Forgot to mention the VM security change that you have to make the first time from the Wiki entry.
# echo vm.mmap_min_addr = 32768 >> /etc/sysctl.d/10-process-security.conf