For some unknown reason the developers of Ubuntu 10.04 Lucid Lynx swapped the order of the minimize and maximize buttons.  Here is how to change it back to normal order.

In Gnome hit Alt-F2 to open up the run box.  Once opened type gconf-editor

Once gconf-editor is open navigate to the apps -> metacity -> general and change
button_layout to :minimize,maximize,close

That’s it.
Update: (2010-05-12)

Even easier way and cooler because its done on the command line is to open up a terminal and while logged in as your user account

Type this:

gconftool-2 --type string --set /apps/metacity/general/button_layout ":minimize,maximize,close"

Update: Thanks to the comment from LMB you can use this command to add the menu icon on the left side of the menu bar.

gconftool-2 --type string --set /apps/metacity/general/button_layout "menu:minimize,maximize,close"