sungrove,

Waiting for Nokia won't do you much good. The procedure for flashing an entire image is fairly similar to flashing the kernel. Have you a linux PC at home? If so the procedure is as follows (this is all documented at http://maemo.org/maemowiki/Flasher_tool_usage):

Download the flasher utility from maemo.org.
Download the kernel image you want to install.
Shut down the n800.
Open a linux terminal, and as root, type: ./flasher --query-root-device
The terminal window will display: Suitable USB device not found, waiting
Plug in the usb cable to the n800
Switch on the n800
A usb symbol will appear on the n800 display
On the linux terminal again, type: ./flasher --flash --kernel <kernel file that you downloaded>
Watch the linux terminal for some useful information. If it succeeds, in the linux terminal type: ./flasher --reboot

Mike.