Use it for radio stuff.
I have my Raspberry Pi's (3B+ and 4) connected to 3 USB SDR devices (RTL-SDR V3, Airspy HF+ Discovery, and RSP2), each connected to a different antenna (VHF discone, HF vertical, and LOG/loop-on-ground for MF/LF SWL). Then I can connect remotely (from the couch, or porch on a nice day) to one of the Raspberry Pi's from my Mac, iPad, or iPhone, and listen to SFO air traffic, or check for HF band openings, etc. I also occasionally run some FT8 or WSPR skimmers on one of the Pi's.
The Pi 3B+ also has a TAPR 20M WSPR board on top, so it can actually transmit a QRP WSPR beacon using a GPIO pin.