The Mini Toolbar In Word 2007
If you select text, Word 2007 has a good idea what you might want to do with it and displays a mini toolbar offering a group of the more commonly used commands that you probably want to use. This is a good timesaver if you are working on a different tab and don't want to switch to the Home tab to perform font related tasks, for example. If you highlight some text and point the cursor at it, the mini toolbar appears faded to allow almost unobstructed view of what's beneath - if you point the cursor at the mini toolbar, it becomes solid and you can select a command to use.
Mini Toolbars Video Tutorial
The mini toolbar sometimes disappears; to get it back, reselect the text or right click the selection.
If you decide you don't like the mini toolbar and want to do things the old fashioned way, you can disable it: click the Office Button > Word Options > Popular, and uncheck Show Mini Toolbar on Selection.