Nifty hardware, here's some stuff to do with it.
RPi builds
This is using them for stuff like Pihole and Wireguard.
https://www.reddit.com/r/pihole/comments/c62np8/pihole_with_unbound_wireguard_vpn_server_on_a/
https://github.com/harrypnyce/raspbian10-buster/blob/master/README.md
https://www.raspberrypi-spy.co.uk/2019/10/pi-hole-oled-status-screen/
https://www.reddit.com/r/pihole/comments/bnihyz/guide_how_to_install_wireguard_on_a_raspberry_pi/
Apt Cacher NG
Package cache, great for RPi because one of the upstream repos is horrible and slow.