Beryl XGL Debian Etch HOWTO
This works on my Lenovo (IBM) Thinkpad X60

Install the libxcomposite1 and mesa-utils packages from apt.

aptitude install libxcomposite1 mesa-utils

Add sources and keyring for the sources to your /etc/apt/sources.list

Add the keyring:
wget -O - http://debian.beryl-project.org/root@lupine.me.uk.gpg | apt-key add -

Add these sources to your sources list:
deb http://debian.beryl-project.org/ etch main
deb-src http://debian.beryl-project.org/ etch main

Update apt:
apt-get update

Install Beryl:
aptitude install beryl aquamarine

Edit xorg.conf:
vi /etc/X11/xorg.conf

Add these lines:

To "Section Device" add:
Option "XAANoOffscreenPixmaps"  "true" # Optional if NVIDIA drivers are used
Option "AddARGBGLXVisuals" "true"
Option "AllowGLXWithComposite" "true"

Example:
Section "Device"
	Identifier	"Intel Corporation Mobile 945GM/GMS/940GML Express Integrated Graphics Controller"
	Option "XAANoOffscreenPixmaps"  "true" # Optional if NVIDIA drivers are used
	Option "AddARGBGLXVisuals" "true"
	Option "AllowGLXWithComposite" "true"
	Driver		"i810"
	BusID		"PCI:0:2:0"
EndSection

To "Section Extensions" add:
Option   "Composite"   "Enable"

Example:
Section "Extensions"
   Option   "Composite"   "Enable"
EndSection

To Section "ServerLayout" add:
Option		"AIGLX"	"On"

Example:
Section "ServerLayout"
	Identifier	"Default Layout"
	Screen		"Default Screen"
	InputDevice	"Generic Keyboard"
	InputDevice	"Configured Mouse"
	InputDevice	"Synaptics Touchpad"
	Option		"AIGLX"	"On"
EndSection

Next we need to create two files for easy startup.

Create the file startxgl.sh.
vi /usr/local/bin/startxgl.sh

And add these lines:
#!/bin/sh
# /usr/local/bin/startxgl.sh
# Added to make beryl start on kde login after upgrade to 0.1.999.
export KDEWM="/usr/bin/beryl-manager"
#beryl-manager
sleep 4
aquamarine &
exec /etc/X11/Xsession startkde

Make it executable:
chmod ugo+x /usr/local/bin/startxgl.sh

Create the file xgl.desktop.
vi /usr/share/xsessions/xgl.desktop

And add these lines:
[Desktop Entry]
Encoding=UTF-8
Name=Xgl-Beryl-KDE
Exec=/usr/local/bin/startxgl.sh
Icon=
Type=Application

That's it!

Now when you login select either Beryl-KDE or just KDE if you dont want to run breyl.