Do you want to understand how GPS or cell phones work? MP3 or JPEG compression? Are you playing with image processing? Solving PDEs? Learning about how to process ice-penetrating radar data used for studying Antarctica? (errrr...that's me.)
Convolution and the Fourier transform are mathematical tools that make all of these possible. I think that the way these tools are usually presented is intimidating and non-intuitive. I think in pictures, not equations, so this talk attempts to give a graphical intuition of what these techniques actually do and where they can be useful, with examples from my own work.