Piclens (now Cooliris) is not exactly new, but I decided to give it another try recently. I like it. Piclens is a browser plug in for all popular Mac and Windows browsers that displays a full screen (3d accelerated) photo wall. It work will all popular photo sharing sites. You can easily scroll through hundreds or thousands of pictures, zoom in on the ones you like, share them, and even run a slide show. That's not all however, it also lets you window shop product searches at Amazon as well as visually search videos at YouTube. Finally they have added a 'discover' section that lets you browse current news by topic. The news mixes popular news images and video. A single click on a video and it starts playing. Zooming in on a news photo will give you a summary of the article, from there you can also open the article in a new tab.
PicLens works will all major browsers on Mac and Windows. I like to see new and novel user interfaces and Piclens certainly qualifies. You should check it out. To get a better feel for what it can do check out the video below.
p.s. Some users have been having trouble getting youTube search to work. It seems to help if you delete one of the YouTube cookies first. You can do this by going to Tools > Options > Privacy > Show Cookies > search for "Youtube" > select "VISITOR_INFO1_LIVE" > Remove Cookie. It worked for me.
The free tagging package itag will let you create Cooliris slide shows of your local photos and movies. Windows only though.