Paste these urls into your address bar, one by one.
set it up (no output) edit
javascript:function grab(url){alert('getting '+url+'\n\nplease wait a moment');d=new XMLHttpRequest();d.open('GET',url,true);d.onreadystatechange=function(){if(d.readyState==4){alert(url+'\n\n'+d.responseText); alert(url+'\n\n'+d.getAllResponseHeaders());}};d.send(null);};
this works edit
javascript:grab('/w/index.php?title=Foo');
this gives gibberish edit
javascript:grab('/w/index.php?title=Foo&action=raw');
... but wget http://en.wikipedia.org/w/index.php?title=Foo&action=raw works perfectly.