How to create a path alias with a query string in the target? I want to link /myownstuff to /stuff?owner=myself

It should at least be possible to do with some module, and with httpd-level configuration, but I don't know how to achieve either of them.
I think you can do this with the Redirect module (it won't provide an alias in its truest form but it will forward you on to the right page.

In .htaccess you could a custom RewriteRule before Drupal's main index.php rule:

RewriteRule ^myownstuff$ stuff?owner=myself [L,QSA,R=301] # QSA and R=301 are optional here


If neither of these work there is a quick and dirty way in a custom module:

function MYMODULE_init() {
  if ($_GET['q'] == 'myownstuff') {
    drupal_goto('stuff', array('query' =&gt; array('owner' =&gt; 'myself')));
  }
}


If you've got more than one path to forward/a pattern etc. you'll have to extend this a bit but the logic will work.

I think the .htaccess is probably the best way as it doesn't actually forward on to the URL but masks it internally which I guess is what you're after.

You might also want to look at hook_url_inbound_alter() which I believe you can use to get this kind of functionality...I've not used it before so I can't comment further though.