made a sketch that connects my c-control i2c thermometer module
to the arduino. the module is based on the DS1631 chip.
it was a bit hard to figure out what the datasheet wanted to tell me,
but once i decoded that it was quite simple 
code and a picture can be found at
http://www.local-guru.net/blog/2009/02/02/i2c-thermometer-on-arduino