WordPress Custom Sidebar is a WordPress plugin by destio that allows you toedit sidebars like posts in admin area and assign them from a dropdown menu to any post or page. It supports flexible dropping via widget for independent theme association.
It’s a matter of fact that people don’t want to code when they just want to change their contents. To keep a website interesting for visitors you can change the sidebars contents in context to the main content. Before you could realize it with different sidebar templates or conditional tags. Now you can do all this great things inside the admin area without any coding. Any anyway: Since we organize informations in databases all contents should be stored there, too.
From a dropdown menu you can easily choose all sidebars you created.
Download and info: http://wordpress.org/extend/plugins/wordpress-custom-sidebar/