What is the fastest and cheapest way to display a point in 3d space onscreen for a particle system? Mabe small tris? I would like to make a particle system that recycles particles in python by relocating them to the emitter position at particle death. A big undertaking, I know. Also, would it be possible to calculate particle say, 1000 positons, in a frame? If not than I should pobably not even try.
that kinda seems pointless since it is not an improvement of the way it currently can be done 
What do you mean not an improvement? 
A particles object recycling its verticies to form clouds of free moving stuff is definately an improvement! [!] All I am asking is wether it is practical.
So, how about it?
can you explain recycling its vertices? %|
If you have a particle system that has say, 20000(insert more zeros here) particles, you would want to recycle them instead of continualy spawning new ones and leting them delete themselfes when they die because this involves a lot of data rearangment for blender (or any system) to deal with. Recycleing would be basicaly just returning the spent particles to the emmiter start and having them beging again. I did not come up with this but read it at:
http://www.martinb.com/threed/animation/effects/
Take a look around and you will find it…somewhere…
I didnt think it would make a diff but i was curious so i did a few tests and i have concluded that reseting the positions back to the emitter via python takes more processing than just using the add object actuator as you normally would to fake particles. 
Ya, that is what I had thought…
Ok then.