I was very confused by this statement, until I realized that you created the widget and were talking about how to get blackout pages to display your widget, and not a site owner unsure of how to copy-paste an iframe tag.
Great job with the widget, it shows all of my reps and the calling works. To answer your question, being on the front page of HN should help. Have you tried the relevant subreddits (r/sopa, r/politics, etc)? Reaching out to Wikipedia, reddit, etc directly?
Have you thought about making this more generic, and/or letting people customize instances of it, so that it can be used for other issues?
We created it as a generic, customizable widget for activists. Anyone could add talking points, a title, etc. We also have a way to browse through the widgets that other people have created. (Although since we made it at a hackathon this weekend, there's not much there.)
We made the SOPA widget and page AFTER the hackathon was done, because we realized it was an ideal use case.
I'm guessing you haven't tested it much yet? My senator's office doesn't even allow the call to go through unless the caller presses '1' to speak with someone, but your interface lacks a keypad! Hopefully you guys get it out before the 18th