Windows Live Writer
I just installed Windows Live Writer and am trying it out. As far as Microsoft Applications go its pretty flexible, and supports a lot of types of blogs. Initially written for Windows Spaces (a competitor to MySpace), the editor is able to update Microsoft's blog sites, as well as many other types and api's (Blogger, Moveable Type, Live Journal, and others). Pretty much making this tool a universal blog updater.
For me the benefit is the ability to do spell checking, because as anyone that knows me knows... I can't spell to save my life.
http://download.microsoft.com/download/f/9/a/f9a19f2d-cec4-4a25-9b0b-eb9655ea7561/Writer.msi
To use WLW against Drupal, you need to use the Custom Moveable Type setting and make the URL, utilizing your username and password.
All posts are done as personal blog entires, not as Stories. WLW reads in your existing categories from Drupal, and allows you to select them prior to uploading. So I have just started playing with it, and will be looking to use this application with our corporate blogging solution, as well as with Live Journal.
In addition to providing text, you can also insert pictures from your local hard drive that will then be uploaded into your blog via the API. Drupal supports this functionality in the latest version (4.7.1). If your Blog doesn't support it, you can also have images uploaded to a FTP site. Again, I am completely amazed at Microsoft's effort to support many different blog solutions, besides just their own.