Sadly, I have no idea how to do any of those things. But I bought a couple of Raspberry Pis, and it would have felt wasteful not to at least do something useful with them.
The obvious choice was home media streaming. The first floor of my place has all the consumer electronics and home networking a tech journalist could ask for, but my second floor was pretty bare. Enter the Raspberry Pi (and a 7-year-old TV that had been gathering dust in a corner as a result of being replaced a year ago).