BuddyPress.org

there are several plugins you can find on wordpress.org plugins for frontend posting, there is even a buddypress frontend posting plugin around here somewhere.

you could also use http://gravityforms.com which is the premium route.

or you could do it yourself http://wpshout.com/wordpress-submit-posts-from-frontend/

ah and there is the option where you can leave access to the dashboard and just css the heck out of it to make it look like the frontend.

I like both the gravity forms and dashboard theming options.