New Jetpack by WordPress.com Update to 2.4 Version provides you a new powerful feature to set visibility of individual widgets using visual ‘IF’ conditions. With this new feature you can easily control on which pages your widgets appears by using the new ‘Visibility’ added left to ‘Save’ button. Click the button and it shows you the control options for widget’s visibility and from there you can select a set of visibility options.
For example, if you want Recent Posts widget to appear only on category archives and error pages then select choose “Show” option from first dropdown and then add two rules: “Page is 404 Error Page” and “Category is All Category Pages.”
Also you can hide widgets using ‘Hide’ dropdown option. For example, if you don’t want the Recent Posts widget to show up on search results pages then select “Hide” and “Page is Search results.”