I created a very simple applet in Processing that plots live data and also has options for saving data as a text file or a screen shot. The applet reads analog input pin 0 (can be changed via the code) and plots points. Axis are relative but this can be changed via code.
Let me know if you can think of some improvements, otherwise this is a quick way to visualize whatever sensor you have plugged into the arduino.
Download here:
Read about it here:
I'm also interested in how others re-purpose this code.