Install Skype in ubuntu is very easy,you just need to follow these steps.

First,open a terminal window and add the Medibuntu repository by this command:

For,ubuntu 9.04

sudo wget http://www.medibuntu.org/sources.list.d/jaunty.list --output-document=/etc/apt/sources.list.d/medibuntu.list

For,ubuntu 8.10

sudo wget http://www.medibuntu.org/sources.list.d/intrepid.list --output-document=/etc/apt/sources.list.d/medibuntu.list

For,ubuntu 8.04

sudo wget http://www.medibuntu.org/sources.list.d/hardy.list --output-document=/etc/apt/sources.list.d/medibuntu.list

Then,add the GPG key to your keyring:

sudo apt-get update && sudo apt-get install medibuntu-keyring && sudo apt-get update

install Skype by type this command:

sudo apt-get install skype

Now,you can open skype at Application->Internet menu.

skype