@dj_steve:
you may be aware of that but this is what I found about kexec on N900 and it seems to be possible to use it:
http://wiki.meego.com/ARM/Meego_kexec_install_on_N900
I hope it will be usefull and I presume that it will be easier to compile an "android kernel" for the n900 than using the maemo kernel to boot android and having all the drivers working.