[dctoedt]

To serve as evidence, its date of publication would have to be established with reasonable reliability. For a fee, The Wayback Machine will provide an affidavit confirming that Document X was archived on their servers as of a given date.[1]

[1] http://www.archive.org/legal/faq.php

[Jach]

Alternatively you could just print it out and mail it to yourself with a seal and never open it unless called for.

[Joakal]

Poor man's copyright seems flawed [0]. Where's the basis for mailing it with a seal having legal grounds?

[0] https://secure.wikimedia.org/wikipedia/en/wiki/Poor_man%27s_...

[Jach]

I'm curious if there's any precedence in the courts. But as far as convincing a judge or jury one way or another, it's some evidence that can help you out in a "he said she said" case. Printed out emails are frequently used in civil cases to help convince the judge of one thing or another, and they're quite easily forged but that doesn't stop them from being considered.

Other methods include putting it in public dirs, pastebin, etc. and letting the internet mirror it for free. Encrypt it if you must, torrent an encrypted tarball if you've got name recognition..