The easiest, most secure way to use WireGuard and 2FA.
A black hole for Internet advertisements
I use it with pi-hole , and as a Tailscale  bridge.
I tried to use it as an alternative workstation (running on sway over arch); the 4K display output is nice, but limited to 30hz, and the machine just isn't peachy enough for my use-case.
OPS - Build and Run Open Source Unikernels. Quickly and easily build and deploy open source unikernels in tens of seconds. Deploy in any language to any cloud.
Raw HID keyboard forwarder to turn the Pi 400 into a USB keyboard
I'm currently working on getting Kali Linux installed and working on my Pi400 with an adafruit screen attached to the GPIO port. It's a convenient size for hand-carrying, and with the screen disconnected it could pass (to the casual observer) as a simple compact keyboard. Especially when paired with the pi400kb "driver" 
That it'll run off of a USB battery pack for quite some time is an added bonus. It's obviously not as powerful as a dedicated laptop but as a "cyberdeck" or an incognito penetration test device, I think it'll find a place of regular usage in my life.
Updates to community repo: grafana, tailscale, traefik, caddy, new grafana8 plugin
2 projects | reddit.com/r/OPNsenseFirewall | 29 Dec 2021
Nine Raspberry Pis power this entire office
7 projects | news.ycombinator.com | 25 Oct 2021
just signed up for 1gig fiber internet, for the first time in my life. looking to use a RP4 for ad blocking, DNS service, and VPN management. what VPN are you folks using, to get full use of your ISP speed ?
2 projects | reddit.com/r/DataHoarder | 2 Sep 2021
Looking for suggestions on what to use my server for…
4 projects | reddit.com/r/HomeServer | 23 Aug 2021
Which custom DNS service do you guys use? Is NextDNS a good one?
2 projects | reddit.com/r/privacy | 4 Jun 2021