If you're looking for a great beginner's project that stays useful after construction, consider this Arduino-powered time and weather display by Timofte Andrei. Using a combination of an Arduino, real-time clock IC, simple temperature/humidity sensor and an LCD module his device can display the data from the sensor along with the time in a compact format. Once mounted inside an enclosure it wouldn't look out of place in most rooms.
Furthermore with the use of some custom characters the display can be personalised and display the neat symbols for temperature and humidity as shown in the image above. To make your own version, check out Timofle's Instructable page. And for more, we're on twitter and Google+, so follow us for news and product updates as well.
If you're looking for a sensor to measure temperature and humidity - check out our HUMID: humidity and temperature sensor module. Designed around the DHT22 sensor, it only requires one digital pin and power - and is easy to use with out Quick Start guide. With a temperature range of -4°C to +125°C with +/-0.5°C accuracy, and humidity at 0-100% with 2-5% accuracy you're ready to measure. For more information and to order, click here.