Here is a class that can be used to get the Netduino talking with the TMP102 breakout from SparkFun (<$6).
I imagine that this approach could be modified to use the I2CBus as well... mileage may vary. Before I forget - many thanks to all the other posters of I2C topics. Your knowledge and experience is very helpful!
For anyone who stumbles on this as I did and wonders what happened to the precision of the temps you can get the decimals by reading the 2nd byte (buffer) and then bit shifting it over 4 times (>> 4) - that gives you a value that you multiply by .0625 for the Celsius information after the decimal point.
It was also annoying to find that String.Format doesn't exist and that Math.Round doesn't work as expected either. I used ToString("") with a format specifier depending on how many places you want.
Hopefully that will save someone out there some time.