I play around with my raspberrypi a lot and try to do meaningful things with it.
Recently I created a setup for blocking all advertisements in my home network use a software called pi-hole. I blogged about it:
How I use raspberry pi at my home to block advertisements on all devices and load webpages fast!
I also have connected an external drive with my raspberry pi and use it as an always available cloud storage. I used openvpn and owncloud to enable this setup. I will surely write an article about how I did it very soon!