Astoundingly useful plugin for widgets

Ever want something to show up in a sidebar for just one particular page?

We just installed a rather fun new feature for our newspaper site, a way for the public to report problems around town by pinpointing them on a Google map. We have a sponsor lined up for just this page, and want his ad to show up at the top of the right sidebar on just that page.

I installed the Custom Field plugin, http://wordpress.org/extend/plugins/...-field-widget/, then created a custom field for the page in question. I called the field "newad" and gave it a value of the Javascript code for the ad. Then I added the Custom Field widget to the right sidebar, and gave it the same name as the custom field, "newad." It works! The ad shows up atop the sidebar only on that one page. Very easy! The custom field feature is very under-utilized in Wordpress, and I plan to learn more and think of more ways to use it.