"Post Dating" your articles/vids etc is one of our favorite features on the site.  It's really easy as well.  Just post an article/photo/video/blog like you normally would, but before you press the submit button change the upload date to whatever day you want it to come out.  You can add the article/photo/video/blog to all the groups/events you want like normal.  When the upload date hits the article/photo/video/blog will publish to the public on the RunnerSpace index and any of the events/groups you added it to.  We use this feature all the time!