Edit: Due to the fact that this article is old, the installation instructions may not work anymore. In order to successfully install the latest version of Skype, please access the skype tag and open the latest article (the one on top).
The latest installation instructions for Skype
In this article I will show you how to install Skype on Ubuntu 13.04, from the command line interface.
The latest Skype version is available in the Cannonical partner repository.
Add the Cannonical Partners repo:
$ sudo add-apt-repository "deb http://archive.canonical.com/ $(lsb_release -sc) partner"
Update the system:
$ sudo apt-get update
Install Skype on Ubuntu 13.04:
$ sudo apt-get install skype
To fix the Segmentation Fault error, do this:
$ sudo sed -i 's/^Exec=skype.*/Exec=bash -c "export LD_PRELOAD=\/usr\/lib\/i386-linux-gnu\/mesa\/libGL\.so\.1 \&\& skype %U"/' /usr/share/applications/skype.desktop
Or follow the instructions in these articles (choose one of this article, they all fix Skype)