It is. I started doing this a few years ago and it's made my life so much easier. I use it as a general file server, so I don't need to keep copies of anything on any of my computers, and if one of them crashes, all I lose is the time spent reinstalling from scratch. Of course keeping everything backed up is important, otherwise if your server tanks you lose everything. I'm slowly building a system with multiple points of redundancy, but for now I just keep everything backed up on some spare space on the one desktop computer that's always on.
There's some other cool stuff you can do. If you use a Linux OS on your server, you can set it up so you can access it from anywhere in the world with an Internet connection. You can also use it as a proxy if you don't trust the wireless Internet somewhere. Of course you have to use a Linux client OS in order to do this (or use something like Cygwin), and its value can be limited by your own ISP's upload limit (in my case it's pitiful), but overall it's pretty cool.
You know you're an audiophile when you insist that music streamed over a network connection loses quality as compared to listening to it read from a local hard drive.
lol i'm not sure if you secure your music files or life document files more thoroughly
^my reaction. i guess the only way from there is.... speakers?