In HyperSpin, one of your 4 Artwork layers can include a particle effect. Actually, a particle effects is a serious possible combination of effects you can apply either to a single image or to a swf file containing multiple images, a movie, or even multiple movies. Basically, a particle effect includes an emitter and several applied effects.
The emitter is essentially a point in space, though it can be comprised of large blocks of space as well. You can set the size and location of the emitter and your image, images, or movies will appear at that point (for a single point) or within the boundaries of a 2 dimensional emitter. The video below demonstrates all of the basic particle effects.
In addition to adding images or swf files as particles in HyperTheme, you can add a layer to represent your particle image in a psd file. You must name this layer Particle#, where the # is whichever layer you wish to use as the particle layer.