Bubble Desktop Wallpaper is a nice and original wallpaper that allows you to have bubbles flying on your screen. You can have any image in the background as your wallpaper and you can add this effect on top of it. The bubbles are transparent and of different sizes, and they look very realistic and pleasant. They will fly slowly across the screen from right to left.
Once installed, the program sits on your system tray from where you can only pause the bubbles, which means that they remain as they were for as long as you want. Sadly, there are no customization options, which is really a shame. It would be great if you could select the amount of bubbles, their size, speed, and color. The little system tray menu also includes a link to the developer's website from where you can download other animated wallpapers for free. If you don't wish to see this effect, you just have to exit the program.
In short, if you are looking for a nice and pleasant effect to add to your desktop wallpaper, Bubble Desktop Wallpaper may be a good choice.