Hi, I just published the first beta of DJD Site Post. The plugin will put a form on the page (or into a post) of your choice that allows registered users and guests to write and publish posts from the front end without the need to leave the site. Media uploads are supported as well as categories (you can even create a new one if you wish), tags, excerpts. You can select not to publish a new post immediately and rather store it for review. Admin gets notified via email.
Right now I am working on the next beta release that will include a widget to display the post form in a sidebar. And another cool feature will be the possibility to also edit existing posts at the front end using the same form.