Osciloscope is extremely useful when debugging low-level electrical data communication, high frequency channels, or just for some fun. In brmlab, we have Tektronix TDS 2002 - a reasonably good two-channel digital scope.
Where to find it: Ax' table in square room.
Remember when using it: Always return it to its place after you are done. Take care to always keep the two probes near the scope. Use it gently, don't let it fall from high places, and so on.
Using it for basic measurements is really trivial. Just connect it to power, connect a probe to Channel 1 connector and turn the scope on. The probe has an auxiliary clip for ground and a main tip for the signal. Two leads in the front panel produce a test square signal. There is a switch between 1x and 10x at each probe; 10x basically means lower resolution, but less invasive measurement - keep the switch at 10x by default.
Just touch something with the probe and press the “Auto set” button at the front panel. After few moments, the scope should automatically calibrate at the proper magnification and you should see the signal. You can tune the wheel labeled Channel 1 to adjust vertical resolution (voltage), wheel labeled Horizontal to adjust horizontal resolution (time).
See also the two videos below:
TODO. The scope has a lot of advanced neat features, like triggers, FFT (spectrum analysis), xy-plot, comparing the two channels, and so on. Google, watch videos on youtube, or just keep pressing buttons. :)