Of course - I have scripts constantly monitoring the web for potentially interesting keywords. I then check google trends data for that topic/keyword and analyze the gradient of the line of best fit over different timeframes. If the gradient is higher than a certain (arbitrary) amount, then I class it as a trend!

Is the gradient just a linear least squares fit?

Not the author. Seems like it, it doesn't look like Google Trend gives other variables, so just simple 2 var regression I'd guess