Edit your source.list file with the following repositories :
deb http://download.tuxfamily.org/osrdebian/ unstable compiz-fusion-git
Add the corresponding key with :
$ wget http://download.tuxfamily.org/syzygy42/8434D43A.gpg -O- | sudo apt-key add -
Compiz Fusion is really great and – so far – stable enough !
Related posts:
This unofficial repository are only for Debian Sid, more information :
http://osrevolution.wordpress.com/beryl-debian/#english_version
for ubuntu this :
http://3v1n0.tuxfamily.org/blog/informatica/linux/ubuntu-compiz-git-repository/