I can’t post a link here, as the video is a javascript pop-up style, but if you go to http://www.msnbc.msn.com/ and look at the top of the page, you should see: “WATCH ‘NIGHTLY NEWS’ VIDEO: Killer Cho Seung-Hui speaks.”
I believe that video has a photo of the actual envelope sent to NBC. I saw the envelope on MSNBC 15 minutes ago and could only make out the $14.40 he paid for postage - the other text was too small to see.
I couldn’t load up the video but that’s good enough if you guys have seen it.