If you like the look of the icons in Windows Vista then iVista 2 offers you the unusual possibility of merging them within OS X.
iVista 2's icon collection of 100 Vista icons for Macs are in PNG format with a resolution of 256 x 256 pixels. The three-dimensional icons combine the best of Microsoft Windows and Apple OS X and these icons cover everything including disks, applications and documents.
To replace a standard icon with one of iVista 2's, open the Information dialog and copy the image to the clipboard. In Finder, select the icon to be changed, click Information and inserts the new Icon. Alternately, you can use an application like CandyBar or IconPhile.
iVista 2 is a great way to add a touch of Windows to OS X.