While working on a Reverse Geo Cache project i came across the need to store variables for future use. Since I roll my own boards this required an external I2C EEPROM. Running into multiple problems while trying to write floats and long int's with typical bit-by-bit writing methods I modified the "EEPROM Write Anything" header file to work with a 24LC256 EEPROM (and others with a definition change).
I did a write up (link below) explaining some of the changes and posted some example code to get things rolling.
http://evolveelectronics.net/?p=920
I hope this helps someone attempting to interface with external memory. Happy Hacking!