It would be nice to have an author-preview feature, so that we could see what our posts will look like before clicking "Send Post" and committing them to go out to the world. Another nice feature would be the ability for the author to change postings for a limited time (15 minutes, or an hour, or whatever) after they're posted, as I've seen on some sites. That makes it possible to correct typos and other so-called "stupid" mistakes easily, while the short time limit still makes it possible (once the limit has elapsed) to treat the posting as a permanent document that can be referred back to indefinitely.