So for reference run the following at the command line of by pressing Alt-F2:
gconf-editor
Then drill-down to apps / metacity / general . There you should find a setting forĀ “button
layout” which should currently read:
close,minimize,maximize:
Right-click and choose “Edit Key…”, change it to read:
menu:minimize,maximize,close
The original 10.04 setting is shown here in case we need to switch it back to the left. I reckon the Canonical aim is to eventually use tabs on the right-side of the title bar a bit like the Chrome browser.
For the setting change to take affect you will have to log out and log back in again.

