In this tutorial we will be installing Skype 64bit for Linux Ubuntu 9.04 using the .deb package which can be freely downloaded from the Skype website. If you are running the 64bit version of Ubuntu you may want to do it this way but keep in mind that you will need to run any updates manually for skype it self. Now if your installing it under the 32bit of Ubuntu then you can install it via terminal that way the package updater will, take care of any new releases for you. Below you will find two links one is for Skype the other for some great note & trouble shooting techniques for Skype under Ubuntu 9.04 from the Ubuntu help forums.
Skype 64bit Ubuntu: http://www.skype.com/go/getskype-linux-ubuntu-amd64
Ubuntu Help: https://help.ubuntu.com/community/Skype#AMD64
Have Fun & Enjoy.