You can go here to "quick post"- it'll set you right up with a new post form. No access to other settings, though; if you want to edit a post or play with the site you have to use the other link.
I'ld like to point out that (if you use the "sign in to post or edit" link) all of you who are registered authors are completely able to mess up all the site settings. You won't do it by accident or anything. But don't log in, click on "entries," and see what happens if you click "delete" on all the posts, because it will let you delete them. And don't play with the templates without being careful. I set it to let everyone do everything because I have think that, on our team, there are probably other people who can do cool things with the permission, and those of us who don't know/care how to edit the templates are smart enough not to play with them.