This tip won't be useful to most people, but it is a fun little feature. You can rotate your screen by simultaneously pressing Ctrl+Alt+D and any of the arrow buttons. The down arrow will flip it upside down, the left or right arrow buttons will turn it 90 degrees on its side, and the up arrow will bring you back to standard orientation. If you use multiple displays, this feature allows you to orient just that display in a particular way.
Alternatively, you can right-click on the Desktop background and select 'Graphics Options->Rotation' to turn your page around in all sorts of ways.