This seems to give me some results with a scavenged Amtel 24C04, pins 1,2,3 & 4 to Gnd, 8 to Vcc(+5v), 7 to Gnd*, 5 (SDA) & 6 (SCL) to pin 2(SDA) & 3(SCL) respectively, on an Arduino Micro, on a breadboard with a 5v IC (KIA7805PI) powered by a 9v Battery
On the 24C04, pins 1,2,3 are A0, A1, A2, to set the address (7bit, starting at 0x50), 4 Gnd, 5 Sda, 6 Scl, 7 is tied to Gnd for write (or Vcc (+5v) for write-protect) and 8 is Vcc (+5v)
The Arduino Gnd & VI (Voltage Input / Reference) are connects to the 7805 Gnd and +5v pins respectively.
This might be some help http://www.arduino.cc/playground/Code/I2CEEPROM
I need to do a write then read it to see if it's really working correctly... if anyone sees anything wrong let me know.
Wire.begin(); // join i2c bus (address optional for master)
Serial.begin(9600); // start serial for output
Wire.requestFrom(0x50, 1); // request 6 bytes from slave device #2
while(Wire.available()) // slave may send less than requested
char c = Wire.read(); // receive a byte as character
Serial.print(c); // print the character