integer LIFETIME = 40; //max amount of spawns at one time
float DELAY = 0.3; //Delay between spawns
vector pos;
vector possAdd = <-1,0,0>; //object appears slightly behind avatar
rotation rot;
rot = llGetRot();
pos = llGetPos() + possAdd;
llRezObject("rainbow", pos, <0,0,0>, rot, LIFETIME); //change object as appropraite
llSetTimerEvent(DELAY);
Here they are in action-









