How to display a block for pages that don't show nodes? My Drupal 7 module creates a block, and then in admin I can make it available for the Article content type only. I would also like it to be available to the result page for a Product Search. This page is not of a normal content type and comes to life in hook_menu().

The path for the results will be avantlink-search-results/search term and I would like it to show the block with the search form again. I would rather not use the PHP code option in the block visibility options so as to keep it simple for users of the module.

The code is viewable on AvantLinker.
I think you may want to take a look at the context module. That allows you to define multiple conditions for displaying blocks.

However, you should also consider making your module only return content on pages that it makes sense to appear on. So the user doesn't have to worry about complex configuration.