Option 1: “Per Page Sidebars” WordPress plugin.

This plugin allows the creation and display of custom sidebars for each page on your site. You choose which of your current themes sidebars will be replaced. The replacement works for all descendants of a replaced page.

In this fashion you can:

  1. Easily create a CMS like site with unique sidebars for every page
  2. Create a sidebar with a Cart widget that displays on store pages created by the WP-E-Commerce page, but not anywhere else on the site.
  3. Use parent pages to create themed areas of your site, without touching a single line of your theme’s php code.

More details/instructions for Per Page Sidebar WordPress plugin

Option 2: “Display Widgets” WordPress plugin.

Avoid creating multiple sidebars and duplicating widgets. Simply add check boxes to each widget in the admin (WordPress v2.8 or newer) which will either show or hide the widgets on every site page.

More details/instructions for Display Widgets WordPress plugin