Super useful and simple: Create a RAM disk for super low latency reads and writes. Very useful when working on cloud servers and you need to write an image file <20 ms instead of the 100ms or so it would take with a cloud attached SSD hard disk. Of course remember this is in RAM so this is not persistent storage, if machine turns off, files will be lost, but useful when you need to use the file right away and then never need it again. Working nicely on Google Compute Engine in the cloud, and now my writes are super fast!
http://www.hecticgeek.com/2015/12/create-ram-disk-ubuntu-linux/
http://www.hecticgeek.com/2015/12/create-ram-disk-ubuntu-linux/