The image in this tweet displays its own MD5 hash. You can download and hash it yourself, and it should still match - 1337e2ef42b9bee8de06a4d223a51337 I think this is the first PNG/MD5 hashquine.
Trick I want to see: a document in a conventional format (such as PDF) which mentions its own MD5 or SHA1 hash in the text and is right