How to get a "zoomed out" code view in Visual Studio?

Starting PowerTools 2013 you will not find this feature. Because it is integrated in VS. For activating this: right-click on the scrollbar -> scrollbar options... ->behavior -> use map mode. Works also with VS2015

The Productivity Power Tools 2012 offers and Enhanced Scrollbar feature along with many others. Also, when hovering over a section of the scroll bar, it also displays a snippet of that code that corresponds with your cursor position (shown below).

Enhanced Scrollbar

In Visual Studio (March 2019) 1.33 you can do this:

View --> Toggle Minimap