Flickroom: Desktop browser for Flickr
The program lets you login to your Flickr account and view photos in your own photostream or those of your contacts or groups. You can also use the search feature to find images from all Flickr users, upload your own images, save images from Flickr, add comments, notes, or share images via Twitter.
I have to say, I'm not that impressed with Flickroom's tools for discovering photos from users that aren't your contacts. I find the Flickr web interface much easier to navigate for that activity. But Flickroom has an attractive user interface and handy tools for keeping up to date with your contacts' activities.
Flickroom also has a few odd features like an integrated chatroom where you can communicate with other Flickroom users. But since the program is still in beta, I suppose any chance to leave feedback for the developer and other users is a good thing.