Twextra takes the 140 character limit in Twitter and throws it away to give you 100,000 characters. They have embraced oAuth, which gets them in the game right away (read the article on how Twitter is killing the Ecosystem).
The editor is rich text, including pictures and video if needed. Apparently you can update via a mobile browser without the rich text as well. Translation of the messages is built in for readers all over the world.
One thing the site did not include is how it sends the messages out. Does it use bit.ly? Multiple tweets? I wish that was more clear, but they do have some good how-to videos.
If you need to say 100,000 words, I think a blog is for you. Not Twitter.