Nitrodesk Photographer's Edition is a WPF application that lets you connect to and manage your photos and photo albums across several different photo sharing services. With Nitrodesk, you can pick any online album and manage it in real-time - updating the album or photo properties, viewing and managing the comments, transferring the photos between services and much more. The app also allows you to backup your photos from an online photo-sharing website to your PC.
This program is great, especially if you want to move photos from one site to another, but don't have them all on your PC to re-upload. How convenient!! The software currently supports the following services: Google (Picasa Web Albums), Flickr, Facebook, ShutterPoint, SmugMug, and Windows Live Spaces.
You can download the beta version of the program here.