From Boudewijn Pelt:
Toucan is made to show your images quickly, with minimal fuss. The easiest way is to use it is to put Toucan in the Dock and drag a folder of images on it. Toucan will then scan the folder and show the images. Alternatively you can start Toucan and open a folder or selected images using the Open menu. By pressing the + key, the image is zoomed to 1:1. One pixel in the image is 1 pixel on the screen. When zoomed, you can drag around the image with the mouse by pressing the Ã?Â¢?? key. Exit the zoomed state by pressing the - key. If you start a slideshow with a single folder of images, Toucan will automatically watch this folder for new images. As soon as a new image is detected, it will be shown at the next slide change. If you add multiple folders or individual images, this does not happen. This allows you to make a hot folder where you can drop in images that will be shown automatically. Useful for fares or parties. It also works great with a wifi enabled camera.