I downloaded and installed PostXING today:

    Project Distributor :: Blue Fenix :: PostXING

The download comes with source code and is packed full of features.  I mostly grabbed it for the cross-posting functionality so that I can more easily maintain the 2 or 3 blogs that I currently run.  The tool not only handles cross-posting but also offers rich functionality for commonly used features such as:

• Inserting syntax highlighted snippets
• It imports all categories from your blog
• Allows for, not only blog configurations but also Ftp configs for uploading images and files

I know that Chris did some work recently on the tool and, although there's not much more to add to make it totally awesome I've already noted that it could probably do with offline functionality.   If you use the tool and have ideas about enhancements you can offer them via the feedback form for the project:

    http://markitup.aspxconnection.com/Projects/Project.aspx?projectId=12