If you haven’t made your computer look like Vista yet then maybe you will at least want to add a Vista wallpaper to your desktop. That Flickr gallery has a wide range of Vista wallpapers that look much nicer than any other Windows wallpaper. My personal favorite is the one located in the bottom-left corner of the thumbnails above.
Another simple addition that I find quite nice is the Windows Vista cursors. Personally I was getting sick of seeing the hourglass flip around when my computer was busy. The blue circular motion is much more…tranquil I guess :D .