I have found that gl.setSwapInterval(1) fixes the tearing i was experiencing.  This command turns vsync on.

I have two problems now.

1) I now have ghosting.  I want to be able to tell the renderer that the screen should be entirely cleared of one frame before rendering another.  Does anyone have any info on this?  Could ghosting be caused by the use of textures?

2) This is less important, but I would like to know why rendering between pgl.beginGL() and end() causes the graphics to render in smaller portion of the canvas.

Here's my test program with the graphics inside pgl block.

import processing.opengl.*;
import javax.media.opengl.*;

PFont myFont;
float a;
int pressed;
GLCanvas canvas;

void setup() {
 size(800, 600, OPENGL);
 fill(0, 153);
 noStroke();
   myFont = createFont("FFScala", 32);
 textFont(myFont);
}

void draw() {
 //frameRate(200);
 
   PGraphicsOpenGL pgl = (PGraphicsOpenGL) g;  // g may change
   GL gl = pgl.beginGL();  // always use the GL object returned by beginGL

 if (keyPressed == true) {
 gl.setSwapInterval(1);
 gl.glClear(GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT );
 } else {
 gl.setSwapInterval(0);
 }
  text(frameRate, 10, 50);
 translate(mouseX-width/2,mouseY-height/2,0);
 translate(width/2, height/2);
 rotateX(a);
 rotateY(a*2);
 rect(-200, -200, 400, 400);
 rotateX(PI/2);
 rect(-200, -200, 400, 400);
 a += 0.01;
 background(255);
 pgl.endGL();
}