This seems like it could be very useful - I'd modify it myself but since this is frowned upon, I'm making a feature request instead:
The particle object emits particles in a cone, with many settings such as growth over time, fade-out and so on. These are all deterministic, so why not allow it to emit particles in reverse?
That is, it would create particles in front of it and ****** them in. There are many cool effects that could be achieved with it, as well as some interesting optimizations. I don't see any technical problems with it either.
Now, as I said in the beginning, I'm fully capable of implementing this. Question is, should I do it or wait for Ashley?