I have posted to the Playground (link) an enhanced version of the Sensirion library for the SHT1x and SHT7x humidity/temperature sensors. My main interest was adding non-blocking methods to acquire measurements from the sensor due to the significant amount of time involved (up to 320 ms for temp and 80 ms for RH at default precision). The non-blocking calls allow a sketch to accomplish useful work while the sensor completes a measurement.
Additional changes include a method to select measurement precision, allowing public access to the dewpoint calculation, and inclusion of the latest formula coefficients from Sensirion for the humidity, temperature, and dewpoint calculations.
An example sketch is included with the library to demonstrate the non-blocking calls while flashing the pin 13 LED as a background task.
Hope this proves useful; I welcome feedback and would be happy to answer questions about the library.