(From their help file) Post2Blog is a desktop blogging client that provides the easy way to compose and add new posts (even if you are offline), helps to manage and edit existing posts in your blogs. Provides integration with Word, Internet Explorer and Firefox.

(From their site) Post2Blog features:

• FREEWARE WYSIWYG (what-you-see-is-what-you-get) editor with complete hot-keys support;
  
• Built-in "Live" spell checking (check screenshot);
  
• "Portable Mode" support (check instruction);
  
• Images are uploaded automatically (supported uploading types: Flickr (see example), file area of your blog, imageshack.us, picturelli.com, custom FTP server);
  
• Post text and/or images from Firefox or Internet Explorer to your blog with 2 clicks only using plugins for Firefox (check example) and Internet Explorer (check example);
  
• Compose new posts in MS Word and post them to your blog using Post2Blog toolbar for MS Word;
  
• Integration with RSS Bandit (rssbandit.org) and Sharp Reader (sharpreader.net) - you can post selected items from these RSS readers using Post2Blog plugin;
  
• Post files, images, documents from Explorer or any other program using "Send To -> Post2Blog" command;
  
• Add Technorati, Del.icio.us, Buzzwords, 43 Things tags to your posts;
  
• Automatically send trackbacks, ping web-services to notify about updates in your blogs;
  
• Earn money using "Insert Amazon Link" feature;
  
• Use built-in smiles for use in your blog;

- Website (here)
- portable version (here)

Reason for me:
- an offline blog editor,
- a portable one and
- has visual HTML rich-text editor (as if I draft in MS Word (and use their formatting) it wont copy-paste nicely in Multiply).

Yes I can use in MS Frontpage or NVU. But Blog2Post is just light (quick to load) & portable. A bit disappointment is that some keyboard shortcut is not as same as MS Office. I dont really use the other features.