picasa-light. For people annoyed by the quantity of UI and JS in Picasa.
picasa-light is built on top of Sinatra using the Picasa Web Albums Data API.
The images are loaded progressively via Javascript, 4 at a time, in order not to choke the viewer’s browser.
The interface is inspired by a minimalist Flickr viewer. I use CSS for showing details only on the ‘active’ picture, and some Javascript for the click-to-zoom feature.