If i can recommend you something - install multiboot on your n900 when you get it. It will make things much easier.

When you want to install custom kernel with multiboot, you will have to:

1. copy the vmlinuz-X.YY.ZZblahblah or zImage-X.YY.ZZblahblah file to /boot folder on your device
2. copy all kernel modules to /lib/modules/X.YY.ZZblahblah folder on your device
3. Create multiboot entry (02-blahblah.item) file in /etc/multiboot.d folder, eg /etc/multiboot.d/02-mysupersweetkernel.item with contents:
Where:
ITEM_NAME describes name which will be displayed on screen while booting
ITEM_KERNEL describes the suffix of your kernel image file and modules file name. It is important that your image kernel file suffix and modules folder are the same, eg. kernel is /boot/vmlinuz-2.6.28.10modified1 and modules are in /lib/modules/2.6.28.10modified1
ITEM_MODULES are external modules loaded at startup, "ext3" is needed, you can add more if you want. I found in multiboot source package more options and described them in this post: http://talk.maemo.org/showpost.php?p...5&postcount=91 you don't need to set any more options than these three, but you can if you need to.

Why multiboot is better, than flashing the kernel? Because:
1. installing new kernel is as easy as copying these files to device
2. if you device cannot load new kernel and reboots, you can always load your omap defeault kernel (no need to reflash)
3. you can have as many kernels installed on device as you want (only rootfs storage sets your limit)

While using multiboot, you have to turn on your N900 with keyboard open. Then you will see a list of kernels (you can see screenshot here: http://www.ngportal.com/micadeyeye/i...d-2/_dsc01607/ , only image I could find via google) and you can choose them by pressing keys on keyboard - key "1" for first option, "2" for second, etc. I have now 4 kernels on my N900: default omap kernel, power-kernel46 with wifi bleeding edge drivers, power-kernel46 with pali modifications and NITDroid kernel. If you have any more questions, just ask. If you find my answers useful, you can click "Thanks!" button under my posts