The first question is – why would you? Whilst the Mac OS X interface seems to have set the bar for one of the best user experiences, it is not the holy grail of user interfaces and this is coming from a Mac user! Hehe.
That being said, however, you can mash-up the best and greatest features of the Mac OS X GUI with that of the linux desktop environment and this is exactly what the blog, Linux On Desktop, does with its tutorial.
Now, I am off to tweaking my Asus Eee PC and see how much I can configure it to look like my Macbook Pro. :D
Image from Linux On Desktop.