Integrate Apture into posterous

Apture is a service that uses javascript to modify web pages after they're published by enhancing links to turn into embedded pop-up boxes with lots of content. You could avoid doing the work to make Posterous recognize all kinds of different embeddable content by encouraging your users to sign up for Apture and integrating Apture into your pages. This would be fairly trivial, I think -- a user would just enable Apture in their Posterous account, provide it with their site key from Apture, and you would include the required line of javascript in that users's posterous pages. Apture would take care of the rest.

Check it out: http://www.apture.com