Search result blank page

When a search is run that generates no results, a blank page is generated. Is there a way to have a custom message like "Your search for _insert_search_term_ returned 0 results. Please try again."

You can change your items/browse.php to generate that kind of output. The total results count is available to you as a variable in that script, so you can easily check whether there were no results.

The best place to look for an example of how you might do that would be the admin-side items/browse page. It displays a message when a query returns no results, as well as a different message if there are simply no items in the archive at all.