Photo Zoom for Facebook for Chrome.

Photo Zoom for Facebook, formerly FB Photo Zoom, is a simple, light-weight extension that integrates directly into Facebook so you can see the larger images of photo albums, profile photos and more whenever you hover over a zoomable image!
What's new in this version:
Change name to "Photo Zoom for Facebook" Upgrade Chrome Manifest to version 2 as required by Google Update options page style Fix an issue with zooming certain images through FB's image proxy