If you'd like a nicer way of viewing yours and your friends' photos on Facebook, PhotoBook is for you.
When Photobook is started, it's necessary to log in to Facebook, to give the application permission to access photos.
The galleries will be downloaded, and will feature every gallery on Facebook that you have access to among your friend list, and your own galleries.
You can filter this possibly large number of galleries by viewing either only friends or only your photos. It would be nice to have more filter options.
However, there is a search feature, which you can use to find the gallery or photo you want.
The viewer is attractive and responsive, and there's even a slideshow option, although on larger screens Facebook photos won't look very good when stretched to full screen size.
If you want to keep the images, they can easily be imported into iPhoto for later use.
PhotoBook is a very easy program to use, and it offers a nicer environment in which to view galleries from Facebook.
However, it doesn't really have enough extra features to make it a definitive image viewer.
If you're a Facebook user who loves browsing your friend's pictures, PhotoBook is a neat way to do so, although it doesn't have many options.