The QN8066 is a fun little FM transmitter chip. It covers the full FM broadcast band and has built-in DSP. You would find this sort of part in car cell phone adapters before every vehicle included ...

Flashing LEDs are all well and good, but they’re even better if they can sync up with ambient sounds or music. [mircemk] has built the LUMAZOID visualizer to do just that, relying on some staple maker ...