Love this idea and application of the photo-booth that NYPL has installed. What a great way to celebrate your users, promote the value of the library and enable your customers to have some fun?
More info: Snapshots from NYPL
Flickr pool of images
PS: If you know the source of this image, please let me know. I need to provide them appropriate credit.
Here's a simple slide from my Big Things talk that I delivered at CIL this past year that adds a bit more to this thinking.