Arduino and PCF8575

Hi,
For two days I've been messing around with the PCF8575 I2C 16 bit port expander and I have finally made something work.
So far I can only send data to the chip, and now I am working on reading from it. In the mean time. Here is the code I used.
It actually is much easier than I was making it out to be. I could kick myself because my moto is keep it simple stupid, yet I never take my own advise.
Anyway I hope someone finds this useful. When I get it to read I will post that as well.

//////////////////////////////////////////////////////////////////////////////////////////////////////////
//
//   Write to a PCF8575 to control the 16 outputs using the I2C bus. The PCF8575 can sink approx. 25ma 
//   but only source approx. 5 ma, so it is best to take your LED's or other devices to ground through
//   the chip instead of feeding them through it. So in my code example the 1's mean that the LED
//   is off, and the 0's mean that the LED is lit.
//
//   12/30/2010 Sonny Schade triath5147@msn.com  Use and have fun. If you make any changes that improve
//                                               this code,Please post it to the community.
///////////////////////////////////////////////////////////////////////////////////////////////////////////




#include <Wire.h>

byte address = 0x20;   // address of PCF8575 with A0-A2 connected to GND "B01000000"
                     
void setup()
{
   Wire.begin();       // join i2c bus 
}

//control the pins 

void loop(){
  
  byte a = B11000000; //controls pins 0 - 7
  byte b = B00110011; //controls pins 10-17
  
  // by changing the 1's and 0's above you can control which pins are on and off. 
  // Remember the chip can sink more than it can source So the 1's are off and the 0's are on.
  
      Wire.beginTransmission(address);   // send the address and the write cmnd
      Wire.send(a);                      // pack the first byte
      Wire.send(b);                      // pack the second byte
      Wire.endTransmission();            // send the data
      

}