This reminds me of a fun story. A few years ago at a cool lan + demoparty event called Instanssi they had a local FM radio station dedicated to the event. It wa

This reminds me of a fun story. A few years ago at a cool lan + demoparty event called Instanssi they had a local FM radio station dedicated to the event. It was then revealed that hidden in that FM transmission was the private key to a litecoin wallet containing some coin. I set about to try and extract the hidden message, but didn't succeed before someone else armed with GNU radio had already decoded the SSTV image from the sideband broadcast. It was a fun challenge, and the person who won taught me a bit about GNU Radio. An amazing piece of software, and a fun memory!