After at least 10 hours of trying I finally did it, got beryl working on my computer. Here's my hardware:
Acer Travelmate 8204WLmi with Ati Mobility Radeon X1600
Here's how i did it:
First I installed fgrlx drivers with this guide using method 2: http://wiki.cchtml.com/index.php/Ubuntu_Edgy_Installation_Guide#C
Then, I installed XGL with this guide (Beryl installed this way didn't work, so don't install beryl yet): http://wiki.cchtml.com/index.php/XGL-Ubuntu
After logout and login fonts were too big and reboot and shutdown buttons were missing from the exit window of gnome, so I had to modify my /usr/local/bin/startxgl.sh file to look like this:
#!/bin/sh
Xgl -fullscreen :1 -ac -accel glx:pbuffer -accel xv:pbuffer -dpi 96 &
sleep 2 && DISPLAY=:1
cookie="$(xauth -i nextract - :0 | cut -d ' ' -f 9)"
xauth -i add :1 . "$cookie"
exec gnome-session
Finally, I installed Beryl from SVN snapshots repository with this guide: http://wiki.beryl-project.org/wiki/Install_Beryl_on_Ubuntu_from_the_SVN_snapshots_repository
Hopefully someone finds this post useful.