Most engineers are familiar with the Fast Fourier Transform (FFT) and would have little trouble using a "canned" FFT routine to detect one or more tones in an audio signal. What many don't know, however, is that if you only need to detect a few frequencies, a much faster method is available. It's called the Goertzel algorithm.
via eetimes.com
I was wondering if I should share this in Google Reader, Twitter or here on my blog, but it's too interesting too forget about it.