I just installed Ubuntu Maveirck Meerkat,and the Minimize/Maximize/Close buttons are default at left-side of window title bar.And if you would like to move them to the right,you can try following methods.

Method 1: change window title bar button layout using gconf-editor.

Press Alt+F2,and type gconf-editor in pop-up “Run Application” window,and then “Configuration Editor” opened up.Navigate to apps –> metacity –> general, double-click the Value of “button_layout” in right box and change into :minimize,maximize,close

Method 2: change window title bar button layout using Ubuntu Tweak.

If you have not installed Ubuntu Tweak,first open a terminal window from Applications -> Accessories menu and run following commands to install Ubuntu Tweak from PPA:

sudo add-apt-repository ppa:tualatrix/ppa
sudo apt-get update
sudo apt-get install ubuntu-tweak

Open Ubuntu-Tweak from Applications ->System Tools menu,and go to Desktop -> Window Manager Settings.Change “place” to right under Window Titlebar Button Layout