Ubuntu 10.04 bring a lot of interesting features on social side, twitter, facebook, and so on. But...
The new Look of the gnome interface contains a strange choice about User interface: The window buttons side !
Left side for window size and action management is, IMHO, a wrong choice.
Right side is what human kind is usefull with.
So to bring back old uses :
Start gconf-editor, and go to the apps/metacity/general configuration to edit the button_layout key, and set:
menu:maximize,minimize,close
(full story and guide here: http://www.howtogeek.com/howto/13535/move-window-buttons-back-to-the-right-in-ubuntu-10.04/). and get your window with the right side ;)