Hello i downloades linux ubuntu and installed that i now i want to get 3d desktop like poeople i youtube have. So please help me get a 3d like in the youtube video (http://www.youtube.com/watch?v=kYgV2GlsufI) or somthing like that

Compiz gives you 3D desktop like this. Check-out compiz-fusion.org for more information on the project.

In Ubuntu it should be easy to enable. Make sure you've appropriate packages installed. Press Alt+F2 and then run synaptic. Then search for and install compiz-fusion, emarald, and the plugins you see in the list.

Once you do that you can enable compiz by right clicking on desktop and going to desktop-effects tab and enabling effects.

One more package that you can install is compizconfig-settings-manager. You can invoke it using "ccsm" or from your menu. It should help you configure look and feel of compiz.

One thing. Even though all this works on most hardwares now still it's helpful to know which graphics card you're using and which driver.