[![FlyaKiteOSX Screenshot](rg/content/images/2006/01/FlyakiteOSXv3.png)
I did found a nice site called FlyaKiteOSX, which looks and feel like OSX (on a limited scale) in your browser window. There is an included Finder, a working copy of iTunes (with some samples) and some other nice stuff.
If you would like to get an impression of OSX without buying a Mac, this will be a good chance.