A local Portland software company, Panic, has a nice little iPad app called Status Board. The app allows you create a message board type of display that can include various elements, including calendar items, Twitter feeds, images, local weather info, and other types of information that can be displayed on an LCD TV.
At Lewis we have a large LCD monitor mounted near our main office. We have been using it in conjunction with an AppleTV to display school photos. When we originally set it up, it was connected to an old laptop and displayed various widgets in addition to recent photos from our school Flickr feed. The laptop eventually gave out and was replaced with an AppleTV. This allowed us to show the photos, but nothing else. I have been looking for a tool that would allow me to continue to display images, but also display other school based information along with the images. Status Board does this quite well.
Status Board comes with several built in modules, and with a little coding, allows you to display other types of information such as charts and tables, even local transit information. I am thinking of doing some work to display information such as the school lunch menu, and our average daily attendance. All in all a very visually appealing tools for displaying information.