Superku, that's a good point about the "camera_Xstperson" loop never stopping. That would explain why my camera.tilt was not resetting...and why sometimes...it would just keep getting bigger and bigger as a variable.

And Malice, that's exactly what I needed, a cam STATE variable to "re-set" every time the function switched..

So, with both of your ideas/advice, now I've got this, and it works perfectly! Thanks guys!

Code:
var cam_mode; //global variable

function camera_1stperson()
{
		camera.x = my.x + 11 * cos(my.pan);
	   camera.y = my.y + 11 * sin(my.pan);
	   camera.z = my.z + 25;
	  	camera.pan = my.pan;
		camera.tilt += (key_pgup-key_pgdn)*5*time_step;
	   if(key_home)
	   {camera.tilt = 0;}
	   camera.roll = 0;
}
function camera_3rdperson()
{
	   camera.x = my.x - 150 * cos(my.pan);
	   camera.y = my.y - 150 * sin(my.pan);
	   camera.z = my.z + 50;
	   camera.pan = my.pan;
		camera.tilt = -15;
	   camera.roll = 0;   
}
function camera_3rdperson2()
{
	   camera.x = my.x - 250 * cos(my.pan);
	   camera.y = my.y - 250 * sin(my.pan);
	   camera.z = my.z + 200;
	   camera.pan = my.pan;
	   camera.tilt = -25;
	   camera.roll = 0;
}

function select_cameras()
{	
	while(1)
	{
		if(key_7)
		{
			camera.tilt = 0;                      
			cam_mode = 1;
		}
		if(key_8)
		{cam_mode = 2;}
		if(key_9)
		{cam_mode = 3;}
		
		if(cam_mode ==1)
		{camera_1stperson();}
		if(cam_mode ==2)
		{camera_3rdperson();}
		if(cam_mode ==3)
		{camera_3rdperson2();}
		wait(1);
	}
}


"To one who has faith, no explanation is necessary. To one without faith, no explanation is possible." - St. Thomas Aquinas