I got Desktop Effects working on an X3100 (965 GMA). Here's how.

[fd9_]

So far everything is working - the cube, the wobbly windows....the whole works. Note that this is NOT Compiz Fusion, this is simply how to enable Desktop Effects in Feisty with an Intel card...I don't know if this works with other cards, I just know it's working with an X3100.

Go to System --> Administration --> Synaptic Package Manager
Then go to Settings --> repositories
Then go to the "Third-Party Software" tab

Click "Add"
Copy and paste the following line and then click "Add Source"
deb http://archive.ubuntu.com/ubuntu gutsy main restricted universe multiverse

Add this line as well using the same procedure:
deb-src http://security.ubuntu.com/ubuntu gutsy main restricted universe multiverse

Now click "Reload" or go to Edit --> Reload package information

Now, open a terminal to install the following:

sudo apt-get install xserver-xorg-video-intel
sudo apt-get install xserver-xorg
sudo apt-get install ibgl1-mesa-dri
sudo apt-get install  libgl1-mesa-glx
sudo apt-get install libglu1-mesa
sudo apt-get install mesa-utils

Note that the libglu1-mesa package might not work, that's OK, don't worry.

Now, the last step. Enter in terminal:

sudo gedit /etc/X11/xorg.conf

Edit the "Generic Video Card" section to look like this:

Section "Device"
        Identifier      "Generic Video Card"
        Driver          "intel"
        BusID           "PCI:0:2:0"
        Option "monitor-TV" "TVOutput"
        Option  "CacheLines"    "32768"
        Option  "DRI"   "true"
        Option  "PageFlip"      "true"
        Option  "TripleBuffer"  "true"
EndSection

Then add this to the bottom:

Section "Monitor"
    Identifier "TVOutput"
    Option "Disable" "true"
EndSection

Reboot your computer, and go to the screensavers (just to make sure this works first):

System-->Preferences-->Screensaver

Preview a few of the screensavers in full screen, and if your system doesn't hang/crash after a minute, then this is a good sign! If your system does hang/freeze, then do NOT, I repeat, do NOT enable Desktop Effects!

However, if this is not the case, then you can go to System->Preferences->Desktop Effects and click "Enable Desktop Effects"

Where's my cube?

If alt+ctrl+arrow key does not work for you, enter the following in a terminal:

gconftool-2 --type int --set /apps/compiz/general/screen0/options/hsize 4
gconftool-2 --type int --set /apps/compiz/general/screen0/options/number_of_desktops 1

Most of this guide was taken from the following:
http://wiki.debian.org/Installing_Debian_On/SantaRosa

Good luck....