I like this idea. Or maybe a checkbox at submission - "this is paywalled" - and have HN offer a link to the Google result for the title of the page instead of a direct link if the box is checked.
>>downan+(OP)
This would be perfect. Anyone else remember those "[scribd]" links that used to be next to PDF submissions? There could be a "[google]" link to the Google redirect page (google.com/url?…).