What I'm going to show you is how to build a your own personal dropbox like service using a raspberry pi and some software called OwnCloud. ownCloud gives you freedom and control over your own data. It's a personal cloud which runs on your own server.
If you don't want to go through the steps for downloading and setup up the software you can download the image I have setup from here
. While I have done everything I can to check this is working it should be understood that you use at your own risk. If you do download the image you can skip to step 5.