I can't remember where I heard about this now... I had thought it was Steve Clayton but I just searched without success. So, unattributed then, here is a cool thing:
Thats's from http://www.google.com/trends?q=c%2B%2B%2C+c%23&ctab=0&geo=all&date=all&sort=0
The top pair of lines is searches (blue C++, red C#) and the bottom is news references. You can run this on a single thing to track it over time or on a set of things to compare them, whatever works for you. Here's what you might demonstrate with a single term:
I bet you those blipups are anniversary articles. Anyway, imagine what you can do with this! Have fun!
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