The Per Page Sidebars (PPS) plugin allows blog administrators to create a unique sidebar for each Page. No template editing is required.
This is the metabox that appears on any page or post you are editing. It shows a list of all sidebars/widget areas built into the current theme. To replace one of them with a custom sidebar, you just need to mark the sidebar you are to replace.
Under Appearance->Widgets, for each page or post on you've activated a custom sidebar, you will see a widget area like this one - named after the post or page on which it will be used.
This plugin adds a "Custom Sidebar" metabox to the edit screens for pages and posts. Leaving the "Activate Custom Sidebar" box unchecked means that the plugin does not change the behavior of that page/post.
This screenshot shows a typical blog running the 2010 theme and displaying the default sidebar.
On the edit screen for any page or post, to create a custom sidebar, simply check "Activate Custom Sidebar" and choose the sidebar you will be replacing.
When you activate a custom sidebar on a page or post, the Appearance->Widgets screen gets a widget area created for that page or post.
Any widgets you put in the custom sidebar's widget area will be displayed with that page or post, completely replacing the chosen sidebar.