Sidebars currently allow any data to be entered into their configuration hashes without validating the content. For some sidebars, such as Static, this isn't a big deal. However, a number of sidebars interact with third party services (Technorati for instance), and it would be helpful if the sidebar could validate its settings prior to saving.

In the technorati example above, it'd be nice to validate the format of the URL, and then to test the URL itself to see if you get good data back.

On a general level, it would be nice to have access to the validations available to model classes, as well as custom validations.