Did You Know You Can Try BSD With VirtualBSD?
VirtualBSD 8.1 was released on or around 4/01/2011 and it basically gives you a pre-defined FreeBSD 8.1 installation with Xfce 4.6 and a range of applications in a virtual machine. It is a desktop ready FreeBSD 8.1-RELEASE in the form of a VMware appliance but can also in a few steps be made to run with VirtualBox.
The desktop has apparently been styled to "resemble a certain OS from Cupertino", but I wouldn't know, and to be honest only the window buttons and decorations strike me as similar and as a cheap attempt at being something it is not. Xfce, even with wbar at the bottom, does not make a MacOS in my view. That said, decorations are easily switched, and with a few themes your buttons will also magically migrate to the right again.