Something that would be really sweet would be a breakout board for something like the ROHM BU8763 (a 3 channel FM synthesis PSG chip commonly used in cheaper cell phones these days).
I know audio isn’t Sparkfun’s forte but something like this would be really kickass. Put a little speaker on the breakout board and turn it into a really mini dev board for the sound chip.
I know a market of 1 person isn’t big but I bet other folks would like to play with a sound chip like that.
Definetly uncommon these days 