The Polish Wikipedia has hacked together a neat little pop-up tool for reporting errors in articles. To see it, go to
click around, and follow the "Zgłoś błąd" link in the sidebar. If you click the middle button, it gives you a form that you can use to report an error with the page you're looking at. That report will then be appended to a problem reports page.
It clearly requires a lot of maintenance of said error reports page to pull something like this off, but perhaps it would be worth trying out for a while?