Your Windows Phone is a great way to share photos. Fotobank is a Windows Phone app that has been around for some time that allows you to search the internet for photos by keyword or category.
Categories include landscapes, flowers, buildings, sports, science and art. Fotobank also has a history of your searches for easy reference. Once you find a picture you like or need, you can save the image to your phone.
Fotobank is a free, ad-support application and you can download it here (opens Zune) at the Marketplace.