A Mesh Object with particle system can duplicate it's children Objects, by using the Dupliverts option in the Object context buttons (F7). On each particle then an instance of the Child Object is copied. If the child object has animation curves attached (Ipo) these are evaluated as well, corrected for the beginning and end of the particle life.
Static particles now also can be used for duplication, with same features as above. In the images to the left you can see a sphere with a particle system which uses a texture to deform the paths (texture channel 8 of a material). As a child, a little sphere was attached, which is being duplicated over the 'static particle', based on the amount of "Steps" as indicated in the Effect Panel.
The child object also has an animation scaling it down it in 50 frames, which is also the 'lifetime' of the particles.