You can have Ubuntu, Xubuntu, Kubuntu and Lubuntu all in the same computer

Human nature seeks variety. Ubuntu may be the most fascinating of the 4 variants but I like Xubuntu, Kubuntu and Lubuntu as well - for different reasons. However, if you have installed one, you won't be able to install other overwriting the older one. And a new installation means tons of downloads (Ubuntu first update downloads about 300-400 mb every time) and reinstallation of your favorite softwares like cheese, VLC, etc.

One way to get flavor of all your Ubuntu derivatives is simply installing the desktops of different distros (provided you have about 10 gb of HDD space).

By simply running the following command in the terminal, one can install Kubuntu:

sudo apt-get install kubuntu-desktop

It will download all the unique softwares along with KDE desktop of Kubuntu.

For Ubuntu, Xubuntu and Lubuntu run the following commands:

sudo apt-get install ubuntu-desktop
sudo apt-get install xubuntu-desktop
sudo apt-get install lubuntu-desktop

I have installed Lubuntu 12.04 LTS and Ubuntu 12.04 LTS over my base installation of Xubuntu 12.04 LTS in my PC and Kubuntu 12.04 LTS in my netbook.

At the start I get options which interface to use and I can choose one of the three as per my mood and purpose. Lubuntu installs with Lubuntu netbook interface as well. Fun isn't it?