Ubuntu menu left to right

In the latest versions of Ubuntu, they tend to have the default theme set to have the close, minimize and maximize options on the left hand side of the screen.

To change this simply go to the gconf-editor (Alt + F2 - “gconf-editor”)

Then change apps->metacity->general->button_layout to have the colon at the front instead of the end.
You might want to re-order the placement of the buttons as well.