arduino-tsiclib is a library for the Arduino platform providing a clean interface to TSIC digital temperature sensors like 206, 305 or similar. It is mostly a cleanup of Rolf W.'s code available at arduino.cc (which itself is based on code from mikrocontroller.net). However, arduino-tsiclib also comes with useful improvements like not dropping precision when returning measured temperatures (like the original code does).
Just copy the library to your Arduino libraries folder. See the included example on how to use the library.
When calling readTemperature(), the sensor is turned on. After reading data has been finished, the sensor is turned off again in order to save power. The downside of this technique is that it takes some time for the code to return which slows down the main loop(). An option for reading data periodically without turning the sensor on and off every time is on my TODO list.