Well, instead of having a mac to learn the operating system, just use a ubuntu live cd and it's a lot like the user experience of a mac, expect there isn't apple crap everywhere.
Or..
Use PC-BSD. In many respects it's even more like a Mac than Ubuntu is because it's BSD - Mac OSX is based on BSD. I'm typing this from PC-BSD's Hubble ver 8.2 right now. I'm going through the same thing that guy is going through except it's not so bad. It's not any harder than learning a new program.
Why am I on a PC-BSD ( which is a BSD type system) OS? Well, I have played with lots of Linux distros and I got tired of all their sameness. I spent 4 days getting Mac OSX Snow Leopard working on my system in a virtual machine and played with it a few days. I really liked some of the way Mac does things. Then I remember reading it had roots in BSD so i started looking for a BSD that was good for a desktop user.
My searches led me to PC-BSD which is actually FreeBSD but it's geared to the desktop user. FreeBSD is more geared to be a server. I LOVE This OS. It's fast, very stable and accept for windows games, I can do anything with it I can do in Windows - just like Linux - This thing will even play apps made for Linux.
It comes with KDE which is a windows like desktop environment, and you can add more desktop environments too for different functionality, look and feel. All the desktop environments are very customizable so you can make the look and feel the way you like. For a windows user, this is like getting an OS with Stardocks Windows Blinds and Object Desktop built in with a fancy desktop theme program on top. (Linux has these "DE's" too)
So now, I'm learning this Hubble and beta testing their upcoming next hot looking version called Isotope. I think I'm going to use these for everything else and just use Windows 7 for games. Yes, it's got a learning curve, but it's not as hard as Linux and looks as good as Windows 7 IMO.
But why do it when you already have a good working OS? Just for a change of pace, to try something different, maybe learn something too.