ok i figured out how to get the clutter UI to run on boot. i guess there is actually two different ways to get this to work. at the moment i have only tested this on Ubuntu 8.04
first and foremost you should have the basic ubuntu-mobile packages installed. a good guide that i have used and seen great success is found
here. in these instructions i chose to ignore the section about rolling back the drivers (not really relevant in most cases)
1. in the normal gnome session. just go to the sessions manager (System -> Preferences -> Sessions) and in the command line just enter desktop-launcher.
this should cause the clutter UI to launch on boot. i dont think this would be the best option however due to the fact that this UI seems somewhat unstable and may not want to be 'stuck' using it.
2.(better option) create a separate session that will boot into the clutter UI. this will give you the option of booting into the Cutter desktop or the typical Gnome desktop. to do this you should have followed the instructions in the link above, including the final command "sudo apt-get install moblin-clutter-home". if you have then follow these commands to get the new clutter desktop setup:
1. create a new desktop file named clutter:
sudo nano /usr/share/xsessions/clutter.desktop
2. enter the following into this new file:
[Desktop Entry]
Encoding=UTF-8
Name=Hildon
Exec=/usr/local/bin/desktop-launcher
Type=Application
3. save the file
4. now copy the clutter script:
sudo cp `which desktop-launcher` /usr/local/bin/desktop-launcher
check and make sure the file copied correctly and then you should be good to go. in your login screen you should be able to select a session named clutter and you should boot into it.
enjoy!