http://www.mysensors.org/build/humidity and http://www.mysensors.org/build/pressure In addition to that the current weather situation is transmitted. Right now the temperature values of both sensors are transmitted to the gateway. This is a bit redundant, but maybe useful when mounting one the sensor (e.g. BMP) inside the building and the other one (DHT) outside of the building.
For information on installing libraries, see: http://arduino.cc/en/Guide/Libraries