Drupal Helper provides a search-able jump-to-able modules listing page currently. I am hoping to add more functionality soon.
Having a module is sometimes useful - if that is what you desire, check out http://drupal.org/project/module_filter - however, installing a module adds weight to your sites and may not be desirable for production. Having a simple browser plugin means it just works for any drupal site, without impacting the site for anyone else.