Microsoft Bing Search sometimes will show a button to see what images look like with transparent backgrounds. It shows up for searches for some company logos, where it says "see which images have ...

Although it won’t create an actual transparent image, it will remove the background for sure. Whether it is a solid color or an image in the background, you can use this method to get the job done.

Google’s Got Logos, But Bing’s Home Page Images Attract Too Fast Company has a fascinating article on Bing’s background images and how they are used to market the Bing service.