At the moment, one of the only ways you can prove your content's age is
by printing it out and sending it to yourself via registered mail.
Don't open the envelope, make sure the postal stamp is well readable.
You can also do something similar with a few online services, but it's
usually not worth the additional trouble (unless you put a novel online
:-)).
However, who realistically does this kind of thing in advance?
One thing you can do which might not be worth just as much in court
would be to use a service like browsershots.org to take an online
screenshot of your page (and check for cross-browser compatibility
while you're at it :-)). It won't stay online forever, however.
In court, I doubt that even Googles records would be accepted as proof.
If the scraper can beat you to the index, you could beat the scraper as
well -- and then the scraper could still claim that you copied his
site. The only thing that often works is that you can prove that you
had the content online before he registered his domain (which is often
the case, as scraper sites tend to have a short lifetime).
Silverstall's advice that your proof of content ownership has to be
100% if you go to court is very important. Without preparation before
it happens, you might not be able to have 100% proof when it comes to
it. If your content is very unique and if it is important that it is
only shown on your site, then it makes sense to prepare for that (print
+ post it). If your content is just something you hammered out over
lunch, then you might want to just hope for the best and instead of
spending too much time on protecting everything, spend more time
promoting your website online to make sure that it is indexed quickly
and that people know in advance that it's *your content*.
All of this of course matters even more if you have a blog or if you
are otherwise syndicating your content: scrapers could just download
your feed and publish it directly (and many do). If you're syndicating
your content I would strongly suggest that you only syndicate a
"snippet", that you include a short copyright statement (perhaps with
date) and of course a link to your original content online. If scrapers
still grab your feed, they'll be publishing all of that as well :-).
Don't make it too easy for them - visitors will still view your site if
they are interested after the snippet.
John