If you want to use the latest snapshot of Beryl, Compiz, OpenCompositing Compiz Tools and Plugins, Emerald, kiba-dock on your Ubuntu Feisty, then you should add Treviño’s repositories. Once you add these repositories, you can install them by using apt-get.
Edit your /etc/apt/sources.list file and add the following to it.
deb http://download.tuxfamily.org/3v1deb feisty eyecandy deb-src http://download.tuxfamily.org/3v1deb feisty eyecandy
After you do that, update your packages and then install your required package.
I get a
W: GPG error: http://download.tuxfamily.org feisty Release: The following signatures couldn’t be verified because the public key is not available: NO_PUBKEY 2D6CFB44DD800CD9
W: You may want to run apt-get update to correct these problems
error - am I doing something wrong?