Earlier I had written about transformation packs for Windows XP to get the looks of Vista and Mac OSX. The latest transformation pack is the Vista to OSX Leopard pack. This pack will transform your Vista into OSX Leopard. This pack is supported on Vista all editions 32 bit SP1. This pack will change Boot logo, Login screen, Welcome Center, Brandings, PC-Properties, Back and forward buttons, icons, wallpapers, screensavers etc.
You can go through the FAQ before using Vista OSX pack.