The Raspberry Pi was one of those things that changed everything when it was introduced. It is a $35 full-blown computer. The applications are endless and I’ve got them everywhere.
My favorite use of a Raspberry Pi is a media center client. Load it up with OpenElec’s XBMC image and connect it to your LAN-based NAS (like the Drobo 5N) and you’ve got yourself a full 1080p and surround sound capable media client with your entire digitized media collection ready to go on demand. I used to build $1500+ media center clients with fancy video cards, liquid cooling, and all that other stuff, but this little Pi changed all that. And it draws so little power that I just leave it on all the time, for instantly-ready movie watching.