An idea that just occurred to me that could be applied to Twitter would be to have color or images in the text box of tweets, so that if you send out many tweets in a row, an image, *ADVERTISEMENT*, can appear in the background.
Imagine the potential of that, say for like Business week magazine. They usually send out like 5 tweets at once all in a row. So when I see them it all takes up a good portion of the screen.
What if Twitter would place very subtle light ads with those tweets that was pertinent or what if Business week or the twitterer could choose what image was in the background to show their own images?
Now you not only speak thru words on twitter but you can throw in an image with those tweets in context.