These transitions require the use of Rehan's ShaderTFX add-on. If you've never installed this before, follow the directions on his website and test they work first. If you've already installed a copy of ShaderTFX (registered or unregistered), you can skip these steps.
There are two installers depending on whether you are running WMM 6.0 on a 64-bit or 32-bit version of Windows. The installer will put the necessary files into, C:\Program Files\Movie Maker\Shared.
Prerequisite: Rehan's ShaderTFX add-on.
Windows Movie Maker 6.0:
Blaine's Transition Pack 3 (64-bit) Installer
Blaine's Transition Pack 3 (32-bit) Installer
After restarting Windows Movie Maker, you should have 7 new Paper Fold transitions with corresponding icons. They all look like the screen is being folded down the middle and then it opens up to the new clip. The only difference between the clips is the color background that appears.
*Note: These transitions require the architecture of WMM 6.0 and can't be made to work on versions 2.6 or earlier. For anyone that wants to customize the background color, check the .xml.