I just upgraded to the new Ubuntu 10.04.
The first thing I noticed is that my Maximize/Minimize/Close buttons are now in the left side of the screen and not the right.
I did some Google searching and found that they did this as an adoption from the Mac platform.
This was not just an Ubuntu change apparently.
So, to move them back if you are used to using Windows and not Mac.
1. Press Alt+F2 to get your run window.
2. Type gconf-editor
3. Click Run.
4. Navigate to apps/metacity/general
5. Open the button_layout key.
6. Change the value to menu:minimize,maximize,close
You can organize any way you want but for me this put the menu on the left and the buttons on the right.
You can leave off menu for a cleaner look.