If you're a Windows user, but like the look of the latest the Mac UI, OS X Mavericks Transformation Pack can put a more Mac-like skin on your familiar desktop.
This is called a Mavericks transformation pack, but it's not quite a perfect recreation of Apple's latest offering. Most notably, it uses iOS 7 icons for a lot of apps, rather than replicas of the Mac icons. If you aren't one to get hung up on details though, you can certainly squint your eyes and pretend to be using a Mac. The developer also made it easy to uninstall the program and revert to Windows' original UI, so there's no harm in trying.