particle physics

is there a way to make a particle system have its own gravity and physics. i made a cool fire foe a jet engine but when it moves it scatters particles everywhere. how can i move the particle system around and have it still lokk like it did when it wasnt moving?

also the particles always want to go down unless i change the z setting on the emitter object. can i change it so they always go up?

http://www.blenderguru.com/videos/how-to-create-a-flamethrower

hopefully this will help this video is good! i learned alot from it