So, a couple of weeks ago i was playing gwars.bsp on the OTB speed and i see that you can make fireworks. How to is shown in the demo below. It's pretty simple and maybe many people know about it.
I thought i'd post it up here because i haven't seen it anywhere here on the forum.
Now what can you do with this? This can be good for screenies of pb2 and decoration of maps.
Some other thing i've noticed is grenades falling at topspeed from the sky (i can't find the demo anymore). It looks for me like rain. Maybe mappers could animate rain like this. A problem that might come up with this is idea could be lag. It's up to the mappers to find out if that's the case.