PicLens is a Firefox extension that allows you to launch full screen slideshows while browsing photos.
With piclens installed you can full-screen slideshows while browsing Google or Yahoo images or Flickr. Piclens works with sites that support media RSS. The image you clicked on opens in full screen with thumbnails for other images on the bottom of the screen.
This is a nice extension to view google or yahoo images to view in a full-screen slideshow.
See the below slideshow image for “flowers” search on google images.