Stencil Alpha Mode (simulating inverted mask)

Steps used in the creation of this example:
1. Drag supernova.tiff into a layer
NASA has some great images for download: http://photojournal.jpl.nasa.gov/gallery/universe
2. Rotation, 0s, 0x
3. Rotation, 20s, 2x
4. Layer > New > Shape Layer
5. Drag out a star shape (Q) in the shape layer, and centre it in the layer.
6. Set Mode to Stencil Alpha to see through the star into the super nova image.
7. Create a text layer above the shape layer and the super nova image.
The text will be visible as the shape layer mode is set to Stencil Alpha.