It isn't too difficult to make your own version of Apples Fusion Drive, and it can give you a nice speed boost without taking away from storage.

The OS X 10.10 Yosemite installer from the Mac App Store in your Applications folder. The installer will delete itself when you install the operating system, but it can be re-downloaded if necessary.

How to Make Your Own Chrome OS Chromebook You don't have to wait until June 15 to get your hands on Google's latest in-the-cloud operating system! Almost any old netbook can be made into a Chromebook.