I forgot the source but I heard about the Editorial Calendar WordPress plugin and perfectly fit a need I had to organize my scheduled WordPress posts.

I like to create a bunch of WordPress posts in advance. In the default list of schedule or draft posts, WordPress shows them in the list by date, though you can sort by the different columns. The Editorial Calendar plugin gives you a calendar view of your posts. But, the really cool thing is you can move them around and the date changes dynamically. You can also create new post right in the plugin.

So, it is a simple plugin but which a graphic interface I find very useful.