Medibuntu

If you just switched from Windows to Ubuntu Linux you might have missed some application like Google Earth or Skype. For easy installation of these applications, some non-free or possibly patent-violating codecs and other programs you could simply add the Medibuntu repository to your system. To do this simply follow these steps (instructions for Ubuntu Hardy Heron):

1. Click on Applications->Accessories->Terminal.
2. Now copy, paste and execute the following line:
   
   sudo wget http://www.medibuntu.org/sources.list.d/hardy.list -O /etc/apt/sources.list.d/medibuntu.list ; wget -q http://packages.medibuntu.org/medibuntu-key.gpg -O- | sudo apt-key add - && sudo apt-get update
3. Run Synaptic (System->Administration->Synaptic Package Manager).
4. Click Reload to get the packages from the newly installed repository.
5. Click on Origin (it's one of the buttons at the bottom left part of the window).
6. Select the first Medibuntu repository, then the second etc to view the packages they include. And install whatever you need.

What I suggest that you install:

1. hot-babe: Read the description and don't forget to add it to the Startup programs (System->Preferences->Sessions). Just make sure that you use the following command to run it or the babe will suck on your CPU: hot-babe -i -n 10
   (But even if you use this command the babe uses the CPU a lot and it's a bit buggy especially if used with Compiz, but I suggest that you try her ;-) ... )
   Here is a photo of the babe (fully dressed) :-P
   
2. libdvdcss2: Allows you to play encrypted DVDs. Also search for and install libdvdread3 using Synaptic.
   
3. Google Earth
4. Skype
5. non-free-codecs: To play some video files that no open source decoder exists for them.