call me a little paranoid but - a RPI security camera. I have it running locally on my network, capturing still pictures of cars/people/things walking by (I live near a train). Its really just a passive monitor, but I'd like to add more difficult things to it like tell me if someone comes within x feet of my house - phone me, or something, it works for now though.
Similar to @msyea - i quit my first job out of college to follow my dreams, to only fail 8 months later with not a lot to show. i never gave up my hopes and dreams, and went back to working for ~4 more years. I've now got a much more solid pay then when i failed ~4 years ago, and have rebooted my efforts (on the side) to fulfill my dream! Never.give.up.
Been in this situation b4 - quit first job out of school after 1.5 years of being in it...couldnt take it. Spent ~8 months trying to start a company to only lose like 10k, and not have a lot to show other than some cobbled together code.
I rebased, and saved up - have a job now paying 3x the amount i made then and some runway to pick it up again and bust my ass this time (with a f/t job)
My first failed cause I listened to people who told me to not continue, and lacked a deep enough network, while trying to pay my day to day bills out of pocket. I should never ever have.