We’ve seen many themes for Ubuntu but the only OS theme left for Ubuntu was, Android.
This Android theme, Genoid, brings Android-styled interface to you Lunux with matching icons, background and wallpapers. Now you can easily change GNOME desktop to Android.
If you are a Windows 7 fan and also own a HTC G1 (the only Android-powered handset), you can now get a free Windows7 theme for G1.
This theme uses the default Windows 7 theme’s background wallpaper, and a few icons from the OS i.e Windows Media Player 12, Firefox icon, Pictures folder.