pressureplate is a block that when stepped on it sends a redstone signal this is an example for a "player pressureplate".
[CODE/]
name="player pressureplate";
id=222;
texturefile="terrain.png";
textureindex=22;
material="iron";
type="pressureplate";
stepsound="metal";
transparent="true";
opacity=0;
toolclass="pickaxe";
harvestlevel=1;
pressureplatetrigger="player";
[CODE]