I am just wrapping up a big project with my 7th graders making temperature measuring robots. The students programmed a robotic arm to lower a temperature sensor into a cup of hot water, send the temperature values to Microworlds EX once a second until the water temperature reaches a lower limit they have set (room temperature). Microworlds prints the temperatures in a text box until the RCX stops sending them. Then a button is pressed which exports the values to separate rows in Excel, where the students graph the data. I'm really impressed that my students stuck with this process because many elements of the system were difficult to problem-solve, even though we did it together. Here's one of the robots a pair of students designed, built and programmed. Very clever!
Here is another design. This one has a wicked action on the arm. What you can't really see and hear in the video is that they programmed a series of beeps and blinking lights before the arm swings over.