Not sure if this might be useful to anyone, but here it is. Try at your own risk.

I installed Mer onto my N900 micro-sd card in a dual boot configuration, as per the instructions here;

http://mer-project.blogspot.com/2010...okia-n900.html

The only difference was that I used the most recent image found here. http://stskeeps.subnetmask.net/mer/0...sting11.tar.gz

This works, but due to waiting for the GL support is not really useable.

Then I configured network access, and followed these instructions for installing LXDE.

apt-get update
apt-get --no-install-recommends install lxde libgtkstylus onboard
echo "exec startlxde" >> ~/.xinitrc

and reboot!

Original instructions found here for N810, but it worked for me on my N900;
http://blog.linuxniche.net/?p=64

I haven't really done much testing yet, but it seems to work reasonably well!

Enjoy!