[development] Activate/Deactivate hooks for modules

I find my self longing for Activate and Deactivate hooks for modules. These hooks would run only when the module is activated or deactivated in the admin/modules form This would give module developers a convenient place to run on-time setup code (e.g. database setup) and a place to do cleanup once their module was deactivated. If there's interest I could create a patch for discussion. Is there another easy way to accomplish these types of setup and cleanup tasks?