If you're browsing a gallery such as the Weekly Top 10 - http://www.ukclimbing.com/photos/top10.html - and click on a photo you can now use the arrow keys on the keyboard to flick to the next/previous photo. The Esc key will jump you back to the thumbnails.
Swipe support left/right has been added for tablet and mobile devices.
Please Note: You need to be viewing a sequence of photos for this to work ie. there needs to be a Thumbnails and Next Photo/Page text link at the top.