Windows/Mac/Linux (Adobe AIR): Flickr users looking for a change up from the standard Flickr site interface will want to check out the lightweight Adobe AIR desktop application, Flickroom.
Once you install Flickroom you'll need to authorise it to access your Flickr account. The application relies on your photostream, groups, sets and contacts to procure photos — you aren't simply searching Flickr with a different face.
Flickroom, right off the bat, gets high marks for presenting photos in a pleasing way on a neutral grey background. The entire application is darker—and while this may be a reviewer bias—it makes it quite pleasant to use and really shows off the colours of each photo. From within Flickroom you can browse through the groups you've subscribed to, view new additions made by your contacts, scroll through your photostream and more.
You can control how much detail about the image is displayed ranging from a simply slideshow appearance to a sidebar with all the description, comments, tags and EXIF data. You can also comment on the photos, star them, make notes, save to disk and Twitter about the photos you're viewing.
Flickroom is free, Adobe AIR-based. and can be installed on Windows, Mac, and Linux machines.