Mads Hobye has created a great piece of software that allows one to create a software "dashboard" for your Arduino. The purpose of this to make life much simpler when debugging and running Arduino sketches, by allowing you to visualise realtime data and Arduino status. In other words, it's a graphical user interface for your Arduino. See it in action during the following video:
This would have many uses, and certainly be very handy when debugging hardware sensors and so on. To get started, visit Mads' project page. And for more, we're on twitter and Google+, so follow us for news and product updates as well.
Although the PC dashboard is super-convenient, you may need to test in the field or away from a computer. In these cases consider using the Freetronics LCD & Keypad shield to display your data. It contains a bright 16x2 character LCD and five buttons that can be read from only one analog input pin: