There are many instances that a wedge might be used to show disruption, conflict, imposing force, dividing force, impact, etc. These graphics provide options to visually depict the many types of these concepts. The very slender wedge is almost like a knife and leaves the entity divided but nearly intact, for example. The larger wedge nearly obliterates the entity. The small wedge can imply a small force, but you can imply a large result if you wish. There are many, many opportunities to create a specific message.
There are variations showing the effects of the wedges as well: a dent, a crack, and a split in the entity.
Customizing the wedges
Group the wedge graphics before sizing/rescaling if there are multiple fields. To rescale, hold the shift key down as you resize.
The blocks and wedges can receive fill and line colors from your palette or any complementary colors. Choose colors for the block and wedge that provide contrast, making the two distinct.
PowerPoint 2007 options
You shouldn't use bevels or glows, since the wedge concept needs to depict real objects. A reflection effect might be okay.
Be careful about applying 3D. The effect may make the crack or split less distinct.
Don't use a drop shadow (PowerPoint 2007) but some of the other shadows would work nicely. You don't want the image to appear as if it is "laying" on the slide, but that it's standing upright. So choose a shadow that helps promote that concept.
Gradients, patterns, and photographs
By all means, use gradients and imported photographs in the block and the wedge. Choose and crop your photographs carefully so that the visual message of the photograph is clear.
There's not a really good way to show the wedge splitting the block. It's probably better to show the splitting process in stages, as shown in the series example.