So, I've been playing Minecraft for several years now. My wife, however, just started playing recently. Naturally, we wanted to play together. Sometime back in the history of Minecraft, the multi-player server code was merged in with the original single player game code, and thus even local single player games are run internally with a client/server architecture. Because of this fact, Minecraft has has a nifty feature that lets you take a single player game you are playing, and "Open to LAN" which makes it multiplayer.
My laptop was powerful enough to run the game with minimal lag for either of us, but this meant that she could not play if she had down time during the day while I was at work. We tried hosting the game off her laptop instead, but it could not handle the load and caused lots of lag and other problems for both of us, enough to make a survival game unplayable. The obvious solution to this was to run a server.
Now, Mojang recently started their own hosting for Minecraft, known as Minecraft Realms. This is a nice self-contained option that handles all the administration and operation for you. There were just two problems. 1) I'm a Linux Engineer. If word gets out that I'm letting someone else run a server for me, I'll never hear the end of it at work. 2) More seriously, there is a monthly fee for using Minecraft Realms. It isn't much, clearly a lot less than purchasing hosting to run your own server. However, I don't have to purchase hosting. I get an allowance of cloud servers through my work (Rackspace, disclaimer at the bottom of the page, all views are my own and not theirs.) and I'm not currently using it all. So, I can have a decent quality server to use for free. Now, I just need to figure out how.