Use Excel to Draw Waveforms

I learned a trick yesterday from a friend's tweet that Excel can be used to draw waveforms using different cell border outlines. I just tried it out and within a few minutes I got a pretty nice waveform in front of me. There is no learning curve involved and no need to purchase and/or install a special waveform drawing tool. I presume OpenOffice Calc can be used to do the same thing.

Below is the waveform in Excel:

And here how it looks like in "Print Preview":