I just recently came across Microsoft’s new blogging client, Live Writer, which allows you to create blog posts to multiple blogging accounts offline, and synchronize, or publish, them your blogs.
The biggest advantage to this is you get full WYSIWYG functionality, and a much bigger area to write your posts.
You also have the added benefit of being able to insert pictures quickly and adjust as needed. There are of course other products on the market that do very similar things, some that integrate directly into your browser, like the Firefox plugin scribefire.
You can download Microsoft’s Live Writer from their website. Although it’s still in beta, it seems to have all the features most people would be looking for.